Unity Project

Before you can begin making pocket rooms, you will need (or at least it will be severely helpful) to have a patched Unity project for Lethal Company. If you don't already know how to do this, you can start by following the instructions here: https://github.com/Zaggy1024/unity-lc-project-patcher#v73-fixes

Registering Unlockables

You will also need to already know how to register ship unlockables/upgrades/furniture into the game. There are a few current APIs you can use to assist in this, such as DawnLib, LethalLevelLoader, or LethalLib. Whichever you choose is up to you. If you also don't already know how to register unlockables, DawnLib has a simple guide on how to use its DuskMod feature to do this for you, with no code, here: https://thunderstore.io/c/lethal-company/p/TeamXiaolan/DawnLib/wiki/4104-c6-ship-upgradesdecors/