How to make a mp3 or wav file into a .bank

I want to replace a games sound with something else but it is saved with a .bank. i converted the .bank to mp3 but i cant change mp3 to .bank please help me! thanks

A bank is created by opening an fmod project (preferably the project from the game) in FMOD Studio, and adding the mp3 as an asset, then building.
Its quite possible it wont work in an existing game though due to bank signature checking.