1994 caravan sliding door problems!!HELP

I have a 94 grand caravan. The back roller on the door fell out and i cant get it back on. Does anyone know how to get it back on? I need this help immediately, snow is coming!

Well I think mine just did the same. 1994 Caravan shorty. Sliding door likes to jam open. Used to be a trick where you lifted the back of the door a little and it would slide. Been a while since I used it, tried to close the door, and the back rollers came off track. Is there a trick to getting them back on track?