They can be a pain to replace it depends on the vehicle. Some vehicles that I wont name (cough*volkswagon*cough) use hex head bolts, and i mean 12 or so of them all around the half shaft to hold it into the the transaxle, or in this case the just an axle. Usually you have to pop out the tie rod end to be able to swing the knucle around far enough to slip the old shaft out and get the new one in. The guide will tell you more or the fine details, mostly because i have yet to replace mine (judging by the new vibration in 4wd i think its time) but that should give u a general idea