My trunk lock for a pontiac sunfire fell apart how do I put it back together

Find yourself another 98 Pontiac sunfire somewhere, and ask the owner to let you see the mechanism, so you can repair it.
You might be crawling inside the trunk and unscrewing the latch or lock in there to release it, and then finding a used pull lever somewhere, or make one from scratch.
God bless your efforts.

Open the trunk from the inside with a screw driver if you can get through the back seat. If you can't, and the key does not work, take a drill about 3/8" in size and drill out the center of the lock. Then take a screw driver and open the trunk. Go to the junk yard and get another lock and have a lock company make a key if needed.

I had a problem with that before on my 2001 Sunfire. It was an issue with the sensor that tells the alarm system that the trunk is open. Make sure the trunk is closed and the trunk wiring is OK.

The toumblers inside the lock are worn or out of adjustment.........Replace.....Hope this helps.

You may have inadvertently locked the latch when putting the plastic piece back on look at the latch mechanism and where the latch locks on the bar put a screw driver in the latch mechanism and then operate the lat to open it should open up then try shutting the trunk lid do it with the plastic piece off first to be sure thats the problem because if you have the plastic piece on you may make it nearly impossible to open it up. Then if it works put the plastic piece back on then make sure the latch is open and then close it does it work? if yes you did it if not write back to me for more help. Thanks for using fix-ya.

they are usually a combination of bars one over the other and sort of spring loaded and locked by clamps you may have to go to what we in Canada call an auto wreckers and see if you can buy the whole assembly and replace it., all the bars if locked in place properly will open the trunk and hold it open until you press or push it closed

for now squirt some WD40 into the lock and work the key in and out untill it opens. then clean the lock with carb cleaner. let dry then find a dry grafite lube and apply while working the key in the lock

See if you can make the latch work by just using a screw driver in the slot to lock it, then open it with the key. If that works ok, you will need to raise the striker and align it to the latch.

yes you need to get a new one and inside they put
some grease in it

open trunk look on inside of trunk lid where lock is .you will see a clip ,just slide off clip remove lock