http://bentasker.i2p/posts/documentation/general/replacing-a-fan-on-thinkpad-x220-x230.html
They're numbered - unscrew 4 first, working down to 1, Lift the cooling unit away Fan Replacement You'll need a much smaller screw driver now, there are 3 cross-head screws holding the fan unit onto the cooling apparatus Unscrew these, and carefully pull the fan away (be careful not to bend the metal, it's thin) Before you fit the new fan, blow any dust out of the exhausts Prepare for the most frustrating stage - getting the new...