It has been 4 years since I had my 99 Trooper, but IIRC the bumper assembly comes off with 4 bolts at the frame rails, and possibly some sort of connectors around the sides to keep it from vibrating. You will need to disconnect the fog light connectors also if you have them. There is a thin sheet metal "bumper" under the plastic...whether you impacted the metal is hard to say, probably not.
95 Trooper LS - 4" lift, 35" tires, 5.38 gears, ARB lockers
Indy4x Revolution 3.07:1 low range gears, Indy4x HD tie rods, homemade sway bar disconnects, Calmini HD sway bars, Darlington diff drop, OME 929 coil springs + 1" poly spacers and 1" body lift, Indy4x HD torsion bars, Indy4x HD rear axle links, Indy4x Kevlar brake lines, ARB bullbar, custom rear bumper with swing-out dual jerry can carrier, rock sliders, Sears Platinum Group 31 battery, ARB mini-compressor, Indy4x kevlar air lines, Warn M8000 winch, Blue Sea 6006 winch cutoff switch, Yaesu FT-1900R 2-meter ham radio, Larsen MHW-150C 1/2 wave antenna, Cobra 18WXST CB radio, Firestik II antenna, generic 8" driving lights, even more generic fog lights, two (2) Blue Sea auxiliary fuse panels, and outofrshell Dave's custom 1" shifter extension. (I actually typed this list as a joke but people seem to like it.)