I can't get the back off to change the battery on my mouse. Imac
My batts are dead and the back won't come off IMac wireless mouse
iMac (27-inch Late 2009), Mac OS X (10.6.8)
pull the release button down with your thumb on the base of the mouse to release the cover
if that doesn't make sense, Google changing battery in iMac wireless mouse to see hundreds of instructions and video's