How could Hitler have won WW2?
1939-1940:
-Same thing, but prioritize research on the StG 44.
-Develop mobile spare parts for tanks that can be used on any tank.
-
Panzerschiff goes back to Germany.
-Give military advisors to Italy.
1940-1941:
-Actively seek battle against the British in Weserubung. Mobilize U-boats and the Luftwaffe to do as much damage to the Royal Navy.
-Push on at Dunkirk. With mobile spare parts it could be done. Make GB lose 340,000 soldiers, shake their morale.
-Scramble U-boats and Luftwaffe. The weather doesn't matter, make GB lose as many people and resources as possible.
-Don't bomb London. Destroy RAF and Royal Navy. They are symbols of Britannia and destroying them lowers British morale.
-After Fall Gelb, Manstein goes to Italy giving the generals a course on Blitzkrieg.
(Assume the British surrender after this)
1941-1942:
-Balkans should fall quickly. Send as little support as possible to Italy.
-Put Kesserling instead of Rommel in N. Africa. Rommel becomes second-in-command. This might be counterintuitive, but a cautious logistician is needed to balamce aggresive Rommel (only neccesary if GB has not surrendered)
-Give an ultimatum to Japan: Go to war with the USSR, and Germany will go to war with USA. This should draw away reserves.
-Put a solid plan for Barbarossa. Give generals enough troops to do the job and nothing more.
-Paratroop at Leningrad and Moscow. If StG 44 is ready, the paratroopers will use it.
-Be friendly to the Slavs and don't waste resources on the SS. They have little use in the war. This in effect absolves Germany of a lot of warcrimes.
-Use spies to make Stalin distrust Zhukov.
1942-1943:
-Paratroop at Stalingrad and Causacus oilfields. Supply with Luftwaffe. Push to Caspian Sea. Use StG 44.
-Train special forces for an attack on the Politburo and Stalin.
-Werhner von Braun's rockets must be able to hit the Eastern Seaboard.
-Tie up the US Navy at the Atlantic. The more of a problem Raeder and Donitz gives to the Americans, the better.
1943-1944:
-Attack Stalin and the Politburo. Destroy any remains of USSR leadership.
-Start bombarding the Eastern Seaboard. New York, Boston, Baltimore, etc. are targets.
-Develop rockets for Washington D.C.
(Russia should lose by now in a two-front war)
1944-1945:
-Bombard USA with all you've got. Break their morale.
*note: some of this steps might be overly callous or cruel, but this is in my pragmatic opinion the best step to win WWII.