get inside with a slim jim then take out the lock cyl. The ones with the chrome removeable covers you can open em up & clean the mini tumblers/spacers/springs. Lube it with powered graphite. On a side note with some spare cyls you can mix/match em so all your cars use the same key (even the trunk) & you can even leave a hole or 2 in the cyl blank, nobody picks locks anymore (except in the movies)