My FJ had an aftermarket front bumper when I bought it...as far as I can figure out it is an Expedition One. Several rock throws have started to rust and so I had planned to pull it and have it Line-X coated (worked very well on it's rusty rock sliders and rear bumper). Fast forward to pulling this bumper...was able to get the 2 inboard nuts off the bumper, quite rusted but a bit of encouragement and they came off. The remaining 6 outboard nuts were another story, they thread on to factory studs the are welded to the end of the frame rail. Nuts hopelessly rusted on, essentially round and almost impossible to access. One design flaw on the bumper is that there is pockets on both sides that hold about 1-2" of dirt/mud with no drain hole to allow this to clear. My guess is that these nuts were swimming in mud most of their life. After about an hour of trying/swearing reverted to the grinder and took the heads of these studs off... a lot less swearing, couple whacks from a sledge hammer and the bumper came off. When I remount it, I'll run the new bolts in the opposite direction so the nuts are accessible from the fender well, a liberal dose of undercoating should slow the rust. Oh ya, drilled a couple 3/4" holes in the bumper, should drain well now. What a PITA, the flesh should grow back on my knuckles in a week or 2.