8/p7/3P2R1/8/1k3K2/3p4/3r4/8 w - - 0 1
The first part of this puzzle was easy. The second part is very hard for me. I need to work the position out with the help the Nalimov Tablebase because I don't quite understand how to win this position.
Though you might want to at least reduce it to a position with no remaining pawns just for some practice.
And it is enough to reduce it to a position you can confirm with the Nalimov Tablebase.