Pretty much have Stalin die early (During WWII?) and theres some chance of this.
Beria wanted to hand back East Germany as he thought a divided Germany would always strive to become unified and it would avoid a future war, but this was seen as abandoning socialism in Germany.
Malenkov also had similar views which Khrushchev called him spineless for.
Molotov as well had thought about unification, but for him and others that any new neutral German state would have be based on East Germany, so had to have some degree of socialism.
So two ways of maybe getting Germany unified earlier is having Beria rise to power through whatever means or Malenkov retaining power with the POD being Khrushchev dying from pneumonia in '47.