On the passenger side backseat door, I've had this problem for a long time where you pull up on the lock and it's really hard to get it unlocked. Sometimes I have to use both hands and pull up on the handle outside to get it to open.

Is there an easy way to take off the door panel and find what's screwing it up, and if so, what would be the recommended tools?

 

First i think you should start with what year car, I'm guessing it doesn't have power locks in it? I would say something got knocked out of line if you have to pull and lift....?