93 XJ6 transmission shifting hard

I have a 1999 XJR with the same problem. I was able to open the door from the inside which bought me a few month's time (the handle worked for period of time from the outside thereafter). As of last week this trick didn't work anymore. I was informed by my mechanic that I need to buy a new handle. He also mentioned that it is not common, but sometimes the rod within the door becomes disengaged---you would need to open up the door panel and reattach it. You may want to check prior to purchasing a new handle.
If it's any consolation, I was informed that this is a common problem.

SWVE
Fellow Jaguar Owner