When the shifter will not release from Park, first, check the brake lights and see if they are working when you step on the brake pedal.
If the brake lights are not working, check the fuse labeled "ST/LP" in the under-hood fuse block. If the fuse is good, the problem will be the Brake Light Switch, located under the driver's side dash, at the top of the brake pedal arm. This switch controls the brake lights and also sends a signal to the shift interlock telling it to release when the brake pedal is depressed. Inspect the electrical connector and wire harness for any loose, broken or damaged wires. Inspect the switch mount and contact points for any broken or misaligned parts. If the visual inspection checks ok, replace the brake light switch.
If the brake lights are working, the problem will lie in the shift interlock system. The shift interlock solenoid, located at the base of the shifter, under the lower concole cover, will need to be inspected and tested as well as the shifter assembly itself.
If you found this answer helpful, please help me by leaving a rating using the "stars" at the top of the page or click 'accept'.
Rating or accepting my answer does not cost you extra. It allows me to be credited for this Q&A.
If you cannot rate or do not see where to rate, please let me know!