It may be possible to remove the pump without removing the pulley, if you don't have A/C. Turn each bolt out until it hits the back of the pulley, remove all the bolts that clear the pulley. Then pry the pump loose, now you have clearance to continue working the bolts out until the pump comes off. Alternatively, you can get the special pully removal tool from Harbor Freight Tools or rent/borrow one from the auto parts store.
Caution! Do not attempt to use a 3-jaw puller, you will destroy the pulley and not get it off. In fact, the pully will tear off the hub before the pulley will come off the pump. Don't ask me how I know this. 
I believe this is the puller from Harbor Freight Tools: http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=40749
JazzMan