The rear bumper - just take off every bolt. I don't really see an incorrect way of doing it
Those plastic things above the wheels are cooled fender flares. You can upgrade em. Although they are expensive. Look up the company Bushwacker.
And when you're cleaning out the engine compartment, also cover the throttle position sensor (it's located on the throttle body) in addition to everything else you are already planning on protecting
If needed to replace, UPGRADE!!
'96 XJ 4-door Sport 4.0L, AW4, NP231, HP D30, 8.25
w/ 4" Teraflex lift, 33" BFG K/Os on Black Rock Soft 8s, 4.56 gears (thank you RWKHausSupply), APN header, Precision Auto Injectors, bored throttle body (thank you Thexjfiles), Spectre Intake, 2.5" Magnaflow catback (thank you mudfrog), Optima red top, Kelley's WiP 4 gauge battery cables (thank you 5-90), 10" cubby subwoofer (thank you KFXHellRaiser), 1-ton steering (thank you SeriousOffroad), front Crusader prerunner bumper (thank you JCR Offroad), sliders and rear bumper/tire carrier (thank you Ares Fab), Hyline Hood Vents, Truck Lite LEDs and more