I know Iím not the first person to have one of my door locks freeze up on me or get so bad that you canít even get the key in. This is just a basic cleaning and lube of your door locks. If you get really ambitious you could try and find new parts but I have yet to do so. I am NOT a certified locksmith or a professional at this, but I have done it to my Supra several times (drive it in the winter and they get jammed up every year).

Link: http://www.supramania.com/forums/showthread.php?39358-Rebuilding-your-own-door-locks-with-pictures