I don't think its too hard. Hitler gets into Art school in Vienna. He ends up meeting more jews and isn't by any means a hardcore antisemite (though he retains some just because of his upbringing and the period he lives in, though it dissipates as he gets older).
He works as a highly trained, but unsucessful artist, he tries to avoid conscription in the Austrian Army and heads to Switerland where he paints, drinks, and lives a mostly happy existence. He eventually returns to Munich Germany where he joins the Liberal German Democratic Party. He states that the Monarchy was the problem Germany entered the War, and feels that true Germans would have settled for Peace, and kept more of its land.
While he does become a skilled orator and political speaker, Hitler doesn't get far in politics due to his background at first, but by the mid to late 20's he is leader in politics in Munich and the DDP. He runs for the Reichstag in 1928, leaves in 1932 and runs for President in 36, promising to take Germany out of the depression while also fighting Communism, and National Socialism. Hitler of course is still seen as somewhat hard to get along with, but he does get the Centre Party, and other Centrist and Right wing parties to join with him, changing his earlier harsh rhetoric towards Germany's upper class, seeing them as necessary for fighting the KPD and NSDAP. Hitler also tries to emulate American programs in Germany, working on public work projects and getting Germany back to work.
Eventually he makes an Alliance with Poland, Czechoslovakia and Austria, to defend against the Soviets in the East. By 1940 and 41 the Soviets begin to mobilise invading Poland and the Baltics. At first, Germany is alone, though Hitler does get Britain France, and Itlaly to join the fight. Spain, which has become a socialist country,stays neutral.
The war seems to be in a stalemate. While the Soviets have been stopped at the Oder Neisse Line, the Germans British and French are unable to push them back. The soviets have also taken Greece and Turkey and are threatening the Middle East. Meanwhile, the U.S. while lending support to the Allies, is focused on its own issues. Japan also is a threat, though it has been taking land in China.
In a controversial decision, Germany allies with Japan, in order to defeat Russia, making it promise they won't attack U.S. or British Territories, not commit atrocities in China. The U.S eventually joins in 1942 when the Russians bomb some of the Aleutian Islands. The U.S then fights the Russians in the West while defending Alaska in the East. Eventually with U.S. help, the Russians are defeated. Stalin kills himself awaiting trial in 1948, while many of his enemies switch allegiances to stay in power in Russia.
As for Hitler himself, he serves as president from 1936-48 before retiring. The former president then returns to Munich where he continues to speak, paint and write. As for his personal life. The former president was a bachelor until he married a Munich Woman, Paula Hoffbauer, in 1930 while in the Reichstag. However there were rumors that he had affairs with a few actresses and film stars in the 30's and due to having no children, it was assumed he was sterile due to an STD caught at some point. Hitler died in 1961 at the age of 71 in January, and was buried in Munich, his adopted hometown