04 GT Drivers side lock stuck?

Lubricate the mechanism.

First use a liquid graphite lubricant for the key lock. Put your key in half way and drip the stuff onto your key, move it in and out and turn it multiple times to distribute the oil. If that doesn't fix the problem then you'll have to take the door panels off to get to the control rods and find out what's rubbing or getting hung-up. I'd use a white lithium grease for those.