Are you looking to repair the parking brake, or are you stuck and need to free the vehicle?
Ok, This won't take too long.
The parking brake is located in the rear brake calipers. If you look at the calipers, you will see a cable going to a pivoting arm on each caliper. There will be a bracket that the cable passes through bolted onto the calipers. By removing this bolt you will be able to unhook the cable from the lever ( even if it stuck on ). once the cables have been unhooked, force the levers back into their resting position ( away from the cable).
Unless the problem is with the caliper itself, your parking brake will now be off.