OK I give up! I have 3 jcp puffer jackets and I have seen the thread
where puffer jackets were disassembled into all there parts. both sleeves, two front panels and back panel.

Looking at the millions of stitches that need to be removed, I don't even
know where to begin. It looks like it will take hours and hours to do.

Is there a good starting point or some good method to use?

I thought I had patience until I removed about an inch of seam and looked at
the miles of seam left to rip.