"step 3"

you should now have a central door locking motor out on both sides, unplugged and unhooked

now you can close the lock on the door with a screwdriver or the like by pushing the catch closed BUT MAKE SURE THE DOOR IS OPEN!!!!!!!!!!!!!!

once they are "closed" you can then try and "lock" them with the button to see if the metal rods are free or stuck, if they are stuck you should be able to regrease the runners to get them free again

they run in little white plastic runners which push in, over time they will either dry out or crack and break because they go brittle which leads them to snag

trying to find replacements may be difficult so try not to break them when you remove them if you need to in order to grease them