I ran into the same problem while trying to disassemble my Max. As you can see in the parts photo, I never managed to disassemble it and simply protected the red bits with hobby tape.
Unfortunately the parts are indeed held together by not just screws but also through those metal studs as well as the pins holding the blue 'belt' buckle. I never tried to remove them so I am not sure if once taken out there won't be anything else holding it together but I don't think there is.
My suggestion in this case when it comes to dealing with this issue in restoring the tower with H2O2 would be to find a jar tall and wide enough to contain it (I suspect you have since Max's other parts aren't small), close the tower and place it upside down in it so that the metal is on top. Fill the jar with the H2O2 but only until the blue plate so that it remains above the H2O2 so you don't risk metal/paint corrosion.