I use my remote to open & lock the doors & the front passenger door cannot be opened manually or with the remote.
My front passenger door cannot be opened- frozen on 2000 Buick Century
If you cannot unlock the door from the inside or the outside or with the remote that would indicate that the lock assembly is jammed. In order to get the door open to repair the problem the door panel may need to be partially removed to access the lock assembly and lock rods. Once the lock assembly is released and the door is open chances are that the lock assembly will need to be replaced.