Updating and Patching an IOS game

I have a puzzle game which is consist of some different puzzle types. Each puzzle types are in different scenes. If i design a brand new scene with brand new scripts and assets, is there a way to update my game in clients. If so how can i do that? Does asset bundle enough for this job? Can i be able to eliminate appstore for this update process?(i mean can i use my own server for an update).

Assume that i want to change a value in one of my scripts, i want to update this specific script without updating entire scene or game. Is there a way to do this in IOS/Android?

Variables
You can create a server backend and request the variable values on game start and cache it either in playerprefs or a data file (xml/json/txt/binary)

Asset Bundles
You can use Asset bundles for new puzzles except that you cannot introduce new code with them.

thanks joshimoo, i will try that, it seems pretty logical.