The seatbelt is locked on the driver's side rear.
Hi there. If the seat belt is stuck in the door jam, keeping the door from functioning then some pressure must be put on the door to get the latch to release. You must be very careful so that you do not put a dent in the door. If that does not work a mechanic would typically remove the door panel from the inside of the vehicle to mechanically pop the latch off. This may then require the latch to be replaced if it is damaged.