Help needed with IG wall repair/replacement

I have a 16' X 32' IG that is in need of some TLC. I bought the house, with the pool a little over 8yrs. ago, and I have been told the pool is about 30yrs old. When we first moved in I needed to replace a torn liner, and the surround of 2X6 plank deck, and most of the plumbing. I had a concrete patio poured, and they coped the edge of the pool and fit in a bead-lock channel for the vinyl liner. I now have at least two of my walls crumbling behind the sheet metal pool walls, and of course, after a bad winter, open the pool to find all but the deep half of the pool empty. I have had more than my share of issues with this vinyl replacement since it was installed.
Here is my issue, most, if not all of the walls need to be pulled off and some repairs done to the wood structure that keeps the wall square. The wood does not appear to be rotten (most of the vertical supports are reusable), but I really don’t know what I’m going to find when I remove each section. First has anyone ever done a "wall-replacement"? Any advise that you can give me before I start?
And second, should the walls have some sort of channel that they sit in on the bottom corner or are they just fastened to the vertical supports. I have some idea as to preparing an "A-frame" to support the wall under the patio, but I’m trying not to disturb all of the existing ground under the concrete. Sorry this is so long, but it required some lead-in. Thanks for any advise you can offer.

I'm going to let someone else you with your repair questions, but just wanted to welcome you to the forum and thank you for becoming a subscriber!

Welcome to the Forum!

30 years is a little before I started my tenure in pools,but I'll help if I can.

Any chance you could get us a pic of the pool and the effected panels - I know it would help me and maybe someone else here has the same style pool.

You can send a pic to poolforum AT gmail DOT com