Piece on the back of the LQ door that goes in the plug thingy to hold the door open has broken off. Anbody know where I could get one of these and how hard it is to replace? Should I just call the manufacturer or are parts like these available elsewhere? It is pop  riveted and don't know about replacing things that are riveted. Any help is appreciated.

Here you go!!!

http://www.horsetraileraccessorystore.com/

Any neighbor or friend with an electric drill and pop rivet gun can do the job in a couple of minutes. It might cost you a beer or two. Total cost would be about 20 cents. Make sure you use stainless or aluminum pop rivets, not steel. You can get them at most big box stores or RV dealers.

BOL  Gard