1999 Ford Expedition jumps forward in park, now stuck in dr

I had a heater core put in last saturday, since then my car jumps when put into park, wont start if its in park and only starts in neutral. Now I figured at first since the guy had to take the whole dash off maybe something got messed up with the shifter line in the column while he put it all back together. I looked under the hood and seen the wire connected to the throttle body, under the accelerator cable was disconnected. I hooked it back up and since it hasnt fixed the problem. So today when I got home I dropped it down into drive, then 2, then 1 and then I was going to put it back into neutral to check the tranny fluid. Its got stuck in 1 and I cant shift out of drive into neutral to be able to get the key out. What can cause that problem?

Could it be the guy who fixed my heater core messed up the linkage from the shifter and now my trannys all screwed up? Reason I ask that is because ive done alot of work on my personal and friends cars before, little things and I once messed with the throttle cable where it goes through the firewall into the engine bay and it messed up the throttle cable.

What do you think could cause me to be stuck in drive? Any way to do a quick fix on it to pop it out of gear? Tomorrow I was planning on trading it in for a 08 charger cause my payments would be half what im paying now. Looks like now I cant get out from under this deathtrap.


Thanks for any and all help, past and present.

Edit: After googling for awhile I found that many people have had this problem with the 99 expedition. Could it be the gear shifter cable itself? Thats why the cable came off?
Also how hard is it to replace that cable? Ive done clutch cables, brakes, tranny filters, exhaust systems (headers to tailpipes), etc. All these mostly done on my 86 mustang GT. So you can say im somewhat of a backyard mechanic, just not enough knowledge to diagnose problems.