Don't. Allowing the leap was not about teaching another advantage, it was about no longer fighting the natural inclinations (and petty squabbles).
I'm not a pitching coach by any means, but my experience teaching hitters (and students) is that you should not try to teach a cookie cutter method and cram everybody in that mold. Work with what they do naturally and build that. If they leap, let them. If they don't, don't make them.
The more you try to teach it, the more you will turn it into an illegal crow hop/replant.