I pulled out all the carpet in a couple 2nd floor bedrooms in my late 1970's house to replace with new carpet. After pulling up the carpet I realized it is probably a good time to fix the noisy floors. I tried to screw down the subfloor, but it didn't help. What can be done? Do I have to pull up the subfloor and replace it to fix? Is this something I can do myself? Do I cut around the wall with a toe kick saw, pry up the plywood, and then glue and screw in new plywood?