[AlohaBra]

Are you going to fix it yourself?
It shouldn't be hard, it's all mechanical, but you've got to have tools.
* First, jack it up in rear and put on jack stands. Then turn the rear tires by hand
* Caliper is easy to check, take the wheels off, use a "LARGE" channel lock plier to squeeze it back in. Maybe a huge screwdriver.
* Drive shaft, look to see if it turns
* After that, the diff or transfer case. Disconnect the Driveshaft at the rear pinion and turn rear axle.
* Might not be the ring and pinion, they also have other parts in the rear diff, like the spider gears, the rear axle splines, bearings. The c-clips are known to break also, if yours use those. If you get this far, you can take the rear cover off and look.
* If all this fail, you can put the rear cover back on and have it towed to a shop, preferably one that does Jeep drive trains.

Expect to pay for several hours (if not more) of work.