1989 Chevy S-10 Parking brake cable

If the cable broke under the dash, and the other cables are good, it should be released! If the rear wheel(s) are locked, locate where the rear cables attach to the front cable, put a vice grip on the cable and tap it rearward with a hammer. Tug on the rear cables, this will help. It sounds like the front broke with age, and the rears are frozen with rust. If worse comes to worse, a hacksaw as close to the backing plate the cable plugs into, and cut!

If the cable broke it should release, if it didn't then the cable is stuck under the truck and you 'll have to try to use vise grips and a hammer to make it go back.

Thanks for the confirmation.