92 corolla trunk lock jammed-HELP!

I just purchased a 1992 corolla for my son. The drivers side tail light stays on, running down the battery. I need to get into the trunk to check out the tail light and the trunk lock will not open. I have the correct key and have tryed my best to get it open. The lock seems to be jammed. Can anyone tell me how to get the trunk open, short of breaking things? Can the lock be dismantled while the trunk is closed? I'd like to avoid paying a locksmith.

This might sound dumb, but have you tried leaning on it in the middle where the latch would be and trying to unlock it at the same time that way? It takes 2 people, but it will work if the latch is stuck. Worked with my DH's Toyota celica trunk.