need help with dist. asap

ya ya its a 71 318 and the end of the shaft has the crew driver like end, but how do i get my old dist gear out and how does the gear attatch to the shaft cuz my gear has a hole that like a pin wouild go in
http://store.summitracing.com/partdetail.asp?part=CCA%2D420&autoview=sku thats the gear i have