Are you able to work on brakes, and do you want to? If so, dismantle, scuff pads with emery cloth (or a flat concrete surface) and put it all together lubing it with this
You can get the front Calipers and Pads off easily. To pull the Rotor, you need to remove the Caliper Bracket, 21MM socket and they are TIGHT.
What year is your Chassis? And How many Miles?
Do you have the rear brakes on slide pins like the fronts, or does yours use the stainless steel drive wedges? With either, you can get it apart and do same as front, but drive wedges are a PITA to get back in place.
Remember, unless your Chassis has the "Dump Truck Nose" you can upgrade to those brakes from a 4x4 conversion company.