This is easy.
1: Rapid Naval strike against major cities and Military Outlets in the USA and England by German/Russian/Italian/Austrian/Japanese forces.
2: Mass Infantry incursion by German and Russian forces, supported by Japanese Aerial Divisions; Against USA, by means of Naval Deployment, making use of their weakened Naval Divisions.
3: Use of Air Raids to minimize resistance is Allied cities, followed by bombing runs over each one.
4: Infantry Oriented assault by all Axis forces against all major Frontlines created in these circumstances.
5: It is impossible to predict what would occur beyond this point, without it occuring in a live Scenario. All that is listed above would have worked, if done in full force, immediately after the Attacks on Pearl Harbor.
This offers the best possibility for Axis Victory.
...Seriously consider though, that the Americans and British only bested the Japanese. Germany's decision to turn on their allied Russia and Italy were the worst mistakes they ever made, and it was they who turned the war around.
Think about it.
Your first reply may be that the USA could have just bombed them.
To which i would reply, that they would be bombing themselves, due to the lack of Naval units to predict an assault well in advance to allow launch time. And in bombing their own allied locales, they would be assisting Axis. Not damaging them.