The material I used is affixed by cutting two rectangular slots in it, doing so in a manner that leaves the partially cut away material still affixed at one end, like a flap. You pull this little flap out of the way, insert the bolt that origionally held your bumpstops in place, tighten it, and let that flap just sort of lay over the head of the bolt. FYI, with my sway bar attached, there is not enough articulation to get contact, at least on my 88 2dr, but with that sway bar removed, one can manage to get some contact during droop, but not very often.
Since I do not have a locker in the front, every fraction of an inch of wheel droop helps keep the tires on the ground, thus helping to insure no loss of traction. If I had a locker, I wouldn't worry about it. But, with a still functional and hard "locking" limited slip in the rear, and open diff in front, I do worry about it. My SWB Trooper RS had a similar front end, and was also limited slip rear, and took me everywhere I wanted to go, and quite a few where I might have been happier walking! No doubt the Montero will do likewise.