Here is the most backyard of all the tools I've use to remove door handles and window crank handles on automobiles: take an ordinary shop rag and shimmy the middle of it in to where the clip is. (Don't fold your rag, obviously.) Then, pull on one side or the other half of the rag, and usually the clip will get caught in the rag, and come off the handle or lever. If you're really lucky, the clip will be caught in the rag, and you won't have to go searching for it somewhere in the door or your shop..