I got a sticky button, the volume up button and cant see anything. Wondered if I can pop the button off for cleaning before I try it and can tget it back on properly.
Yeah, they're designed to snap off and click back on. The Geniuses actually have a fancy little tool to do it, but it's basically just a plastic stick with a little fork at the end. Just be firm and don't push down too hard with whatever you choose to wedge under the key. A fingernail has worked for me, but it seems harder on the rMBP with its thinner keys.
They can fix it, but if you have any apple authorized repair shops in your area (not "the apple store") I'd suggest calling around. The shop I worked at in the past kept a drawer full of dead keyboards specifically for freebie key replacements.