Replacing the on/off switch

I followed the Ifixit guide to replace the on/off switch assembly. Stripping to fit the replacement was ok and now I run into a problem. The switch itself on the assembly sits behind the rear camera, but I can't find the spot where the switch must sit. There is also a "oblong" metal ring attached to the on/off button itself that is also "in the way" I followed the instruction to replace the rear camera in an effort to see if I can find an answer there..to no avail. Anybody have experience that can shed some light.