The keys on these Macs are comprised of 5 or 6 moving parts: the black cap that has the extruded letter or symbol, a translucent body that has a number of snaps, a two-piece scissors mechanism made of white plastic, a silicone rubber "cup" and in some, a stainless steel wire guide. All snap together onto the body and onto metal guides on the printed circuit on the Mac itself. around the microswitch that's nestled inside the rubber "cup". That cup's springiness is what pushes the key back out. Awhile back, one "leg" on the scissor of my left Caps Lock broke off and the key proceeded to pop like a Mexican Jumping Bean. Apple said it was "cosmetic damage", "not covered by warranty" and they would kindly repair it after I plopped $800 and waited while they replaced the entire top case (whole chassis, including Laptop Keyboard and trackpad), for ONE FRIGGIN KEY. Needless to say, I purchased a collection of keys (5 for the price of 4; needed 1, but I'm sure another eventually will die and wanted to make the cost of the product bigger than the cost of shipping!) from replacementlaptopkeys.com, watched a couple of YouTube videos and got the Mac back in working order 15 minutes after the postman showed up and I feverishly tore the envelope open.

So I can tell you with full confidence that the only way to get that clean is by lifting the caps. Yeah, that will make the AppleCare guys most unhappy. And yeah, I'm sure more than one of the keycaps will get damaged in the process and require replacement. At $4.95 a pop, with discounts if you break many, just make sure to order the correct type; my Late '11 MBP has type AC01.