How to decompile a build?

Hello,
I’ve just got a big problem, i’ve imported some objects and my player’s prefab deleted himself… But, instead of recreate this prefab (lot a time) I want to decompile one of my old build, but I don’t know how to do this?

Cordially.

Unity is not a round-trip tool.

There is no way to “decompile” a build back to a unity project.

Thats what backups are for.