Where is the waterpump on a 1995 Subaru Impreza and do you have to remove radiator to replace ?

The waterpump is driven by the cambelt. It is under the big black plastic cambelt cover at the front of the car. It is not absolutely essential to remove the rad but it is only 4 bolts and two hoses to get it out and it gives you alot more room to work. I would change the cambelt while I was there also to be honest. It will all have to come off again when you change the belt soo.... If you are not familiar with changing cambelts and timing it up I would let a pro do it. It is not worth the chance you might mis time it and ruin your engine.