Smart thing for China to do would be to offer him a cushy life in exile within China and replace.
Sadly, for the sake of the world, we need to let KJU go unpunished.
Let him live out his days in a cushy mansion in China so that he doesn't start lobbing nukes everywhere.
I believe that to be the sanest course of action.
If KJU tried to "go rogue" (especially if it meant betraying his own country) he'd be dead within a heartbeat. Accidents happen.