How do I clean behind the trackpad on a late 2010 MacBook Pro?

The tolerances in the unibody macs are very, very tight and the area is located behind the battery, so Apple does not recommend users without training on servicing the delicate back sides of the battery clean it other than spraying air lightly from the outside. I've found setting it up vertically and open helps with gravity bringing the grit towards the most open side of the trackpad. (The part closest to you that swings free and presses on the physical spring.)

It's not hard to find the tools or the steps - iFixit.com has both, but I prefer to take it in to the genius bar for cleaning as long as it's a convenient trip. If you're careful, you should be able to get inside the mac and see how much debris is inside and whether it's worth a trip to the shop or to learn how to clean it better yourself. Getting the back off is all you need following the memory replacement instructions to have a peek.

Some other basic ideas:

• Power off the Mac, wipe the area down furiously with cotton balls and isopropyl alcohol. This can't hurt unless you get so much alcohol in the trackpad and onto the battery that it doesn't evaporate before you power things on again. Capillary action can "wick" liquid extremely well, so be frugal if you are not familiar with cleaning computers with alcohol.

• Use compressed air to blast around the borders of the trackpad to dislodge any hand salsa (etc) that's stuck there. This is best done before cleaning with alcohol or after it has dried.