Frozen rear door

Over the winter, my driver side rear door (97 XJ) refused to open up. The lock seems "frozen" but no it's not the temperature-type of frozen. I should add, NO POWEER LOCKS, they are manual.
Any ideas? I have no "real" factory manual/book, other than the lame Chiltons.
I found no reference to this anywhere on .
Help! Thanks in advance.

Remove the plastic door trim. Reach inside and activate the lock/latch mechanism. Clean and lubricate the latching and locking mechanisms, make sure all the operating rods are connected and function smoothly. Use a good quality oil on pivoting parts and a light lithium grease on sliding parts. WD-40 is neither.

I use marine grease, oil tends to leave.

Got my mechanic to take the door panel off - NO ROOM to move, poor guy is 6-2!
The door panel broke, of course, but after 45-minutes, he was able to get the mechanism loose, and the door now opens. Plenty of lube, but now nervous about locking it ever again.
Amazing vehicles, aren't they? Only in a Jeep do you have to worry about things like these!
THANKS FOR THE HELP!
:clap:

Same thing happened in my '99. I parked it after a run on January 19th, and I went into it the other weekend and the driver side rear door won't unlock, both while trying to use power, or trying to push the unlock lever. That's on the list of things to do this weekend.

At least my windows aren't stuck down again.