door lock

New to the forum. I have a 1999 2500 GMC Suburban. where you put the key in from the outside, it has pushed back into the door and now I can not unlock or lock it from the outside. Do I need a new part or can I fix this by taking the inside door panel off?

About the easiest way to solve this problem is to remove the door panel,pull out the door handle,and spray a little lube on the lock cylinder.On the bottom of the lock cylinder is a small catch that holds it in position.Sometimes with age they will not hold and work there way out of the handle.With the key installed you can push the catch and the cylinder will release itself from the handle, but in your case it has already came out.Inspect the handle for wear in the area were the cylinder slides in.Normally a little lubricate will loosen the internals of the cylinder,slide it back in place and you should be good to go.GoodLuck