Undo tie rod ends, steering lines and mounts and steering column shaft. Pull rack out. Counting the turns of the tie rod ends and checking the new rack is the same length as the old one is best advice I've got.
If you have a good tool kit and solid stands yes it's not too bad but you really should still get a wheel alignment done afterwards. You need some good quality pipe spanners for the hydraulic lines though. If you don't have them don't try it you will mush the pipe nuts.