need to replace trunk lock

Find the part that is stuck and grease it. That should solve the problem for years without the mess of re-keying the lock. I had a similar problem on a T44 series trunk lock that cleanand lub corrected.

You should check to see that there aren't any vacuum leaks in the locking system.

The vacuum system works fine for all the locks in this car. I just can't turn the key in the lock. You think spraying graphite or something in it would lubricate it so I can turn the key?

You might have excellent results if you take that lock out and apart to clean and grease each of the tumblers and the cylinder. You were going to take it out to replace it anyway! Or take it out and have a locksmith free it up for you.

That is if the liquid you inject inside of the lock does not get it to work. Marvel Mystery Oil has done pretty well for me. I just started using it and it has freed up some stiff or "frozen" locks. It was on sale at Menard's for under $2.00 for a large spray bottle. Give it time to work and work it over time like 1-2 days. ;-)

I would not invest in that used $65+shipping one unless yours is broken!

You are right! thanks for your reply; I'll dissassemble, clean, and reassemble, hoping for the best, and use that $65 for a nice dinner out.

AND let us know how that works out for you! ;-) Look for that little pin that holds the tumbler/cylinder in. Some vehicles I can remove the tumbler/cylinder without removing the lock.