In 1936 Germany remilitarised the Rhineland. How did Hitler achieve this?

Hitler did
this by being bold enough to try it.  If the French had resisted, the Germans would have had to
retreat.  But the French did not know this and did nothing to stop the
remilitarization.

In remilitarizing the Rhineland, Hitler did not have to
fight.  There were no foreign troops in the area.  It is just that Germany was not supposed to
have any troops there.  After some consideration, Hitler sent three battalions of troops across
the Rhine into the Rhineland.  The French Army massed on the border between France and the
Rhineland, but did not enter to try to prevent the militarization.

Hitler
accomplished this, then, simply by being bold enough to send troops into the forbidden area.  He
got away with his gamble and the Rhineland was remilitarized.