You start as white! send the moves, please!

White wins this game by Black sacrificing his rook.

If you're looking for a solution where White wins even if Black is trying, there isn't one.

1. f7! Rg2 2. f8=Qf8 and rest is about technique.

1.f7 Rg5+

@-waller-

You are right.

after f7 black will play re5+   2. kg4   re4+    3.kg3    re3+     4.kf2    re4   now can you make the winning move???

There is no stopping black from swapping his rook for the pawn. Salvaging a draw can be as good as a win and I suggest that's what's happened here.

waller! I think you judge too quickly! please think more. thank you all! well who wants to solve?

White can win! if you don't want to think, ask me to solve it! ok? I'm here!

After 1.f7  re5+  2.kg4  re4+  3.kg3  re3+  4.kf2  re4  we reach to this position:

White cannot possibly win. Q+K vs R+K is a draw if there aren't any pawns. 

1. f=Qf8

dear helltank! please pay attention to that position. the pawn are now free and the rock cannot attack it! but what's the winnig move? is it f8=queen?

then black play rf4+ and queen takes rock and it cause stalemate! but find a way to win!!!

Q+K vs R+K is not a draw. I've analyzed it.

Then take rook and check-mate. Black rook on h4 will die after Kg3.

First, Q+K vs. R+K is a win, but hard to do.

Second, from the position above, it is still a draw! After 5.f8=R (I guess this is what you were thinking of since it resembles the Saavedra study. If the Black rook was on e4 this would be a win for White. As it is though, with the rook on g4 Black can just play:) 5...Rg2+ and this is still drawn.