The best way, IMO, is for the KH to get the idea that " they want you to leave", but hope you do it on your own without them telling you.
JWs hate needy people, they also hate people who act strange and blurt out what they are thinking.
I know a pioneer who was in a car wreck and she had a head injury. At first everyone rallied around her, until they discovered her personality had changed. She said whatever she was thinking- oh sister, why are you wearing that outdated rag? Oh, sister, why don't you have something done about that mole on your lip? Oh, brother that suit looks like a homeless bum slept in it last night. Yep, she couldn't help herself and they couldn't do anything to her as she had a medical condition. They lived in fear that she would just say something weird at the WT study- and she did. So they all gave her the cold shoulder until she got the idea to fade away all by herself-
added- the "you reap what you sow" applies to anyone who leaves a cult- their is no way to leave painlessly.