Bf6 Kh7
Rg7 Kh6 (Kh8 loses to a discovered check)
Then the knight is pinned and the black king is stuck on the H file, so the white king can move up and trade down to K R vs. K? You'd just have to make sure you don't get forked by a knight check when moving up.
But that seems too simple so I'm probably missing something.