Replacing Socks and Repainting Legs:
Others in this thread have made good contributions on this subject. I will attempt to provide some more info here.
Removal of the wood strips is accomplished while the speakers are erect. When that's done, you will have to lay them down to remove the legs and connection plate. I used some cardboard boxes wide enough to support the wood frame edges. As you are laying them with the Mylar side down it is important not to damage on the membrane.
Turning them over once the Sock is in place means lifting and turning the horizontal speaker. This is awkward with the weight and length of the panels. I grabbed them in the middle between the two support boxes. It was easiest, for me, to reach under to the wood edge on the far side with my right hand while grasping the near edge with my left. Tilting up with the left hand, then lifting and rotating the panel toward me from underneath with my right, seem to work well.
Remember to check support alignment to the panel edges when you twist them over on supports like the boxes I used. It's easy to move the supports when attempting this maneuver. It is also easy to get enthused with your progress near the end and forget simple precautions.
The wood strips need to be identified when removed. I just used "LL" for left side, left speaker, etc. I marked them at the inside top edge so I knew where they belonged. As others have stated, splitting the wood strips is a real possibility! Proceed cautiously and in slow deliberate steps. I used Paco's suggestion of a narrow screwdriver to pry them up from the recess itself. A second screwdriver or similar tool can be used to hold them up while working from nail to nail.
If the wood starts to bend too much, back off. The nail head has to break the wood fibers to allow the strip to come loose in most cases. I only had one nail remain in the strip, and that was at the bottom. Get the small screwdriver as close as possible to the next nail position before applying more force. You can always take a break leaving the next nail for later.
The nails are not all applied in the center or straight. If the exposed putty looks close to an edge it's likely that the nail is at an angle. Guns are fast and lead to such errors. With such a nail it is possible to split part of the wood at that edge. The pressure is increased due to twisting the wood at that groove face.
With supports laid out in front of the panel you can tip it down for easy removal of the legs and plate. As you remove the XO wires from the back of the plate, please mark them as others have stated. You'd be surprised how often you get distracted and then forget. I applied some masking tape to stick them down so they wouldn't get tangled in the fabric as it was slipped past.
The fabric is stapled in the two grooves at the speaker top. The small screwdriver works with some pliers to remove them and those at the bottom. The fabric is folded and some staples are not apparent at first. Make sure you have removed all of them before pulling on the fabric.
You should pull the fabric up at each of the nails. You can do this for many when the speaker is still vertical. I just pinched the fabric at the nail, but the weave makes the process slower than anticipated. Once the staples are gone and the fabric loosened from the nail heads you can remove it.
I turned the speakers over so the magnet side was down while removing the fabric. Shifting the boxes while holding the speaker against my side in a kneeling position with one hand allowed pulling the fabric on both side while pulling it away from the edge. It is easy to snag the fabric when it bunches so caution is advised here as well. Fortunately, the cloth doesn't tear or ravel.
If you work the lower fabric into a gathered bunch about 20 inches from the bottom, you can shift that box support past the fabric to the bare speaker frame. Proceed with the central section by pulling the fabric from the near edge of the gather away and towards you from both sides. It's easy to slip over the nails this way to another gather near the top support box edge. Then you can shift the top box into the central section as you did with the lower one. Now, the fabric can be completely removed as before off of the speaker…if you remembered to remove the top staples!
If you get new fabric, as I did, you will need to turn it inside out before installing it. If you are going to reinstall your fabric, keep it bunched when you remove it so it will be easier to start installing it.
I attached the legs and stood the speaker up to install my fabric. Gathering the fabric at the top so it won't be draped down resisting your pulling. It isn't difficult to avoid snagging on the nails by pulling the edges away from the frame as you pull it down.
Keep an eye out to align the seams with the groove. It doesn't have to be perfect as you can grab the edge of the panel under the fabric and twist it on both sides simultaneously. I worked the fabric taught, pulling on it by grabbing both the sides. I stapled the fabric at the top grooves before trying to stretch it down tight. You can press the taught fabric onto the nails if the seam is straight. This keeps the fabric in place while you work on the bottom. Once I reached the legs I returned the panel, membrane side down, to the boxes to finish the bottom.
My fabric didn't have a lot of excess at the bottom. I trimmed about 2.5 inches off of the rear side curving the cut back to the existing edge near the seam on each side. Pulling the fabric taught, checking on seam alignment, I stapled the rear edge to the bottom near the front side. The cut was determined by trying this stretch first. Pulling the fabric edge taught I put in intermediate staples towards the outer edge. I used just one, then pulled the fabric right to the edge and stapled it down.
I folded the ends diagonally and stapled them to the frame's bottom groove near the seam pulling the fabric towards the center of the panel. Then, the front side fabric edge can be folded like a sheet and over itself just less than the 2 inch thickness of the speaker panel. The folding over of the fabric increases the layers at the bottom. It also provides a folded edge to the fabric at the rear side of the panel bottom. Check for any fabric bulges and alignment as you make this final fold and staple application. I stretched and stapled working from the middle out, tackling the ends last. You'll need staples at front and rear to secure the total.
I used 1 7/8" wide clear package tape to seal the bottom, similar to Magnepan's technique. As the fabric drags along the floor with shifting of the speakers, it is easy to pull on the exposed edges.
Do not cut any holes in the fabric until you've reinstalled the wood strips!
It is tempting to cut the hole for the plate as the speaker sits there on the boxes, all stapled and almost finished. Holding off, you need to locate the bolt hole for the legs and using a nail or such start the holes in the fabric. Threads can pull and gather the fabric. You'll need to do the same when it's time on the plate as well.
Attaching the legs allows replacing the wood strips in the vertical position. Once you check the holes against the nails sticking through the fabric, they're fairly easy to get back on. I had a rubber mallet which was handy for forcing the strips into the recessed groove, tightening the fabric. You should have some folded fabric to protect the surface from a hammer's tapping. The strips will not get to a straight position without numerous taps along their length.
Now the hole for the rear plate can be cut. As you saw with the original, a large enough oval to reattach the wires to the posts is all the manufacturer made. It doesn't have to follow the edge of the wood as XO holes other made needed to do. You don't need to staple the fabric as it will be covered. The screw holes should be found by feel and opened with a nail or peek through the fabric for the screws.
PAINTING:
I had to paint the legs to match the light fabric. It is difficult to adhere paint to the existing surface. I would recommend a thorough sanding with a medium emery paper, or treating it with sulfuric acid. I did neither and suffered some flaking from the bottom edges in a couple of places.
I bought some spray enamel: Rustoleum Gloss Protective Enamel; Antique White. It worked fine, spraying the plastic caps as well; but you have to wait at least 24 hours as it takes a long time to firm up.
Put the legs back on with the speakers horizontal as the weight can dent paint that hasn't firmed enough.