The cause of a jammed or difficult to open door is the insertion of foreign things and dirt in the cylinder or there is some rust in the door lock mechanism. It could also be because of the weakened spring in the door lock, it could be snapped or broken. It could also happen due to the loose screws or frame, the forced turn of the cylinder key, the age of the door, and much more.
You can use the minus screwdriver and a hammer or any metal stuff that’s thin enough and can be hit on the edge of it. Then, find the door hinge so you can lubricate it. Hit or knock the hinge with the hammer until all of the screws are off and the hinge has been removed from its place. If all of the hinges have been removed, then you can tear out the door a little by little. You can learn more on https://da247locksmiths.com/.