Its pretty easy.
Remove Battery.
Remove Hard Drive.
Remove any Ultra Bay devices.
Remove two screws on bottom (middle) to remove Keyboard.
Remove the Easy Button cover on top of keyboard.
Lift Keyboard.
Remove the CRU insulator.
Remove the fan bracket (either snap-off type or 2 screw version)
Remove fan.
When installing the NEW fan, remember to apply thermal grease
to the area that contacts the CPU.