i had to replace a spring on my yj. took my father and i about 6 hours (due to a bolt that WOULD NOT BUDGE). Make sure you have a propane torch, breaker bar, and a cheater bar. jack up the frame, and the axle. Take out the u bolts to release the pressure. Then take out the bolts through the bracket mounts. If you can't get them loose, spray some pb on them, heat them with the torch for about a minute, spray some more pb, let it cool, then heat it up one more time and have a go at it. Heat is a life saver with rusted parts. For installation, do the oppsite.