2003 Ford Expedition rear door hatch

Honestly, it doesn't sound like a lock problem. If the window will open, the lock is off. To me it sounds like a linkage problem. On your model year, I never had to remove the inner panel with the hatch closed. I will tell you on other models, it can be done. There are a few screws along the bottom of the panel that need removed first. Then there are plastic clips that attach the panel to the door that will pop off when you pull on the panel. THere is a tool to use to remove them without breaking them, but because the hatch is closed, you won't be able to use it. Check for screws first, then see if you can pop the clips.

Let me know what you find.