Use a tool like UnrealPak or a community-made to bundle your new .uasset files into a new .pak / .ucas file.
Place your modified file into the game's Content/Paks folder. Most modern games require a Global Metadata update or a specific Mod Loader to recognize new pakchunks without causing a crash or "corrupt data" error. Key Considerations pakchunk10-SaturnClient_s1.ucas
Use FModel or UModel (UE Viewer) to open the .utoc and .ucas files. You will need the specific AES Encryption Key for the game version to see the contents (usually found on community discords or specialized API sites). Use a tool like UnrealPak or a community-made
your content in the Unreal Editor to convert it into a format the game engine understands. Key Considerations Use FModel or UModel (UE Viewer)
Developing a "proper feature" for a file like typically involves modding or data mining games built on Unreal Engine 4 or 5 (most commonly associated with Fortnite or similar titles using the "Saturn" codename).