I've just gone thru this on a '91 reg. cab ranger. There are 6 bolts, 2 on the sides of the rad support, 2 under the carpet/sound deadener where your feet go, and 2 behind the seat under the carpet/sound deadener. I ended up breaking 4 of 6 bolts, the top halves. I used a 4.5" grinder with a zip disc to cut the [what looks like but is integral with the nut] washer from under neath. I found that cutting beside the flat of the 'nut' and removing the pieces the easiest/safest. Be very careful; USE a FULL face mask, leather gloves, and long sleeve shirt!!! Then you can remove the rubber 'washer' with a screwdriver and pop the rest thru the top of the frame mount [ with the cab lifted up]. It seems like the metal parts are made so you can't over tighten them, but they rust/weld together over time.
Hope this helps.
Richard