after 7.5 years, my oem rear shock on my 96' 4runner with 50k miles let go and was dripping oil. what a royal pain in the whazoo to get them off. because they use the threaded rod tops and get mounted to a very out-of-reach place, it is impossible to get the nuts off. sawzall with long blade to hack off the rod from the bottom side, cutting through the rubber gromet and through the rod works, but definitely is tight quarters.... oh yeah, you need to take the tires off the rear to make working on them a bit easier...
replaced with a set of monroe sensa-trac. they go back in real easy, just a bit tricky locking down the top nut with a 14mm deep dish socket and ratchet. easier to tighten most of the way by holding ratchet steady while turning shock body, then ratchet to lock it down...
since i installed rear bilsteins on my 2002 tacoma today in about 20 minutes, 4runner was a bear in comparison....