The .rar file you mentioned typically contains a .nsp file, which is a package format used by the Nintendo Switch. It is important to note:
: Ensure your console is connected to the internet. The update should download and install automatically when you launch the game. Super.Mario.Maker.2.v3.0.2.NSP.Update.rar
: Downloading game files from third-party sources can expose your console to malware or lead to a ban from Nintendo's online services. Official updates are always recommended for stability and security. Version 3.0.2 Highlights Super.Mario.Maker.2.v3.0.2.NSP.Update.rar
: To use these files, a console is usually running custom firmware (CFW). Super.Mario.Maker.2.v3.0.2.NSP.Update.rar