Just lubricated the fan in my 1470 (which is the Time Capsule, not the Extreme, but all iFixit effort seems to be going here). Just wanted to note firstly: as others have stated you can pull the fan straight up off its PCB (after removing cover), give it some lubricant, and it may be good as new.
Other note: all cables on my unit (possibly newer?) were routed in/under things and not as easy to remove as shown here: had to remove the metal plate (step 3) before I could do step 2; could not remove the fan without removing the cover to the power supply (as I was trying to lubricate I left it in situ)