Keys sticking on MacBook Pro 2011

A lot of my keys on my MacBook Pro are sticky feeling. Do they just pop off so I can clean them or are there special tools needed to remove the keys? I don't want to risk breaking the keyboard.

Edit: On a slightly related note does anyone know what key type the 2011 MacBook Pro uses? Specifically looking to just replace the comma/left arrow key ,<. Does it use ac01 or ac05?