The .rar file is a container. Use a tool like or WinRAR to extract the contents.
Ensure your console has the latest sigpatches installed. Without these, the Switch will fail to launch custom NSPs. FUSER-NSP-ROMSLAB.rar
To "prepare" or install this content, follow these general steps for a modded Nintendo Switch: 1. Extract the Archive install the Base Game first
If the .rar contains multiple files, install the Base Game first, followed by any Updates and then DLC. FUSER-NSP-ROMSLAB.rar
You should find one or more .nsp files inside, which are the actual game or update packages. 2. Choose an Installation Method