The answer is for black to play R-g5. If white then plays RxR, black recaptures with the pawn and wins. If white plays R-d5 check, black captures the rook and wins. And of course, if after black plays R-g5, white plays Kxh6, black just takes the rook and wins.
I hope you found the answer. Look for another new challenging chess strategy puzzle in my next post! If you would like to have these puzzles sent to you, just add your email address in the “Subscription Options” box and click “Subscribe.”