U joint replacement can be intimidating but really it is pretty easy. Driving the new ones in (or old ones out) with a hammer will work in a pinch, and as long as you dont hit the journals. I have found that a vice is quite helpful and easy to control for pressing new joints into place. Obviously, the jaws need to be able to open wide enough to accomodate not only the joint but also the slightly undersized socket you'll use as a ram. Take your time and you'll get a lot of satisfaction when you're done.