2. Don't stop before Dunkirk for whatever stupid reason you did - push them into the sea and destroy the army and equipment they had left.
3. Finish Britain. Those, whatever, 100+ extra subs you have via cancelling the stupid surface fleet ships? Sick them on Britain. Not a fucking shit gets through with anything for the island.
4. Do NOT invade the SU. At least not when they did. Instead, once the UK falls (or even if it did not fall, but it would), drive from Africa into the Middle East and take the British oil holdings in the Middle East (if they did not cede them to you already in their negotiated peace).
5. While you are seizing more oil than you can ever use, CONSOLIDATE you holdings. Production, production, production. Increase it. Exponentially. ALong these lines, don't be a moron and extirmate so many people when they could be helping you build weapons of war. Absolutely, positively maximize weapons of war production.
6. With the British holdings in the middle east under your control, rather than trying to slog hundreds (thousands?) of miles to Moscow, strike from the middle east directly to the SU oil fields near Baku and what not. They will fall very quickly. The SU will not have sufficient oil to field any kind of armored or mechanized units.
7. From there you can do pretty much whatever with the SU. You will be far outproducing them, and you will have more fuel than you can use and the SU will be desperately short on it. However, come as LIBERATORS, not killers. Respect and show respect to the people you conquered, who hate the SU in general. Have them join the effort in new units.
8. Game over for the SU. But, to be ABSOLUTELY sure of total victory, tell Japan that, if they knew what was good, they would attack the SU intstead of teh US. Attacking the U.S. was probably the worst military decision anyone made. EVER. With Japan attacking the SU from the east, and you from the south and west, it falls relatively quickly.
9. The U.S. will absolutely, positively stay out of it given these facts and circumstances.
Germany would have one the war, and she and her allies would spread from Europe to the far east.
How would you advice Hitler to win WW2?