Did I break my Kwikset SmartKey lock by trying to rekey with a key that doesn't fit all the way?
take the lock to your local home store that carries this line of locks. they will remove the core and put it in a SmartKey Reset Cradle. this returns the lock to an unprogrammed state.

there is no way to do this yourself without disassembling the lock core, and there's about a bazillion point 2 pieces in there.