That's exactly the way I would do it. While it should be OK to remove all the rails at once, I would just do 4-5 at a time and work on that area. You might have difficulty if you do not plan on raising all of the liner. It looks like you have enough slop to pull the molded part of the liner over the wall and install coping. But I think you would have to do this all the way around. The heavy molding might prevent you from going back and forth from coping to the j-hook hanging over the wall. Unless doing some trimming with a razor knife would help. Your other problem area will be around the skimmer. I assume it has been installed so you really cannot do much adjusting in that area. You would probably have to blend from overhang to j-hook.

As you get into it you will find out if it can be done with a full pool or whether you need to drain some water to get more stretch in the liner.

Dennis