Just did mine 2 weeks ago. Concur with Jim--hardest part was getting the fan off. I removed the old pump with the fan attached, and set the impeller in a bench-top vice to hold it in place--came off easily. Took about an hour and a half of cursing at the thing to come up with that, though.
One other problem I encountered was getting the pipe to seal properly in the pump. I thought I had it right, but every time the engine heated up, it sprayed coolant out between the pipe and the pump. After reseating 3 or 4 times, it seems to have stopped (knock on wood).