Update prefab inside another prefab unity 5

I know this has been asked before, but most topics i found are years old. Problem:

I got many Level-Parts as prefabs which can be stuck together to form random levels.

They contain many other prefabs like monsters and traps. If i change an other prefab, the ones inside the level-prefab wont get updated.

Is there any way to update them without expensive extensions? I mean its unity 5 now and i still cant find a solution.

@Lordloss Your question is a bit vague, what exactly are you trying to update, for example do you want to update the material or position?

I know this thread allready and it doesn’t help to solve the problem, sry. Yes, it is an instance of the prefab.