amplex

This is a difficult one to fix. Anything that falls in the slot in the armrest that the latch catches jams the release.

Best option: buy a new seatback from a salvage yard (~$200). Next best option: buy a replacement armrest, making sure you get the upper latch mechanism from the seatback and the hinges.

Ok - I'm guessing you don't want to spend any money on this.

Step 1 - remove the seatback from the car. Other posts discuss how to do this.

At the top center of the seat are two bolt heads. These are the bolts that hold the top retainer in place. On the backside, where you can't currently reach them, are self locking nuts. Drill or grind the head off of the bolts, being careful not to light the seat on fire.

Remove the fabric covering the back of the seat and you will find two plastic 'push-pins' in the center of the seatback, about 24" below the bolts you removed. Remove the pins.

Once the bolts and pins are removed you can fold the armrest down. You will have to work the plastic cover over the back of the seat as you do so. With the armrest folded down you can remove the 4 torx screws that hold the hinges for the armrest and remove the armrest along with the latch from the seatback.

If you have a new armrest and latch you can install it and put the car back together.

I was able to pry the latch mechanism out of the armrest without damaging the armrest, though it did break the portion of the latch that attaches to the seatback. It still works but I'll probably order a replacement.