To release the parking brake:
* If it's a pedal: Simply push the brake pedal down. If it's stuck, you might need to gently rock the car back and forth while depressing the pedal.
* If it's a lever: Lift the lever. It might have a small button or release mechanism you need to press while lifting. Again, gently rocking the car might help.
If the parking brake is still engaged after trying these steps, there could be a mechanical problem (like a cable that's frozen or broken) and you'll need professional assistance. Don't force it.