I'm working on intalling rear lift shackles on my 89 excab 4x4 and having a very tough time getting the shackle bolts to break free from the spring-eye bushings so that I can remove the old shackles. Any tips? I've hit it, pried it, heated it. Am I going to have to cut these things off?? Any help would be great. Thanks!

89 xcab 4x4 22re. 1.5" BJ spacers, 3" shackle and AAL + fender trim. 33x12.5 R15 MT/Rs, 15x10 rockcrawler streetlocks. 488 yukons by ZUK, detroit rear and true-trac front. 2 1/4" cat-back exhaust. Redline gear oil. Rear bumper by bentup.com.