Without any monkeys paw effects or backfires?
(Note: I know the way I’ve worded the question may actually sound quite ill intentioned, but in reality it’s far far from it. Forcing this person’s iron clad will to change on this matter is essential to two lives, one being that of a young child, which it’s destroying until it’s fixed. I mean no harm upon this person, I just need to force them to do something they’re determined not to do, which actually requires NO effort on their behalf to do at all!)