To successfully use this file, you generally need to follow these steps based on common practices found on community forums like r/SwitchPirates :
It looks like you have the first segment of a multi-part compressed archive for on the Nintendo Switch. This specific file name indicates it is the NSP format (Nintendo Submission Package) and includes Update 1.0.17 .
: Since this file is labeled as "Update 1.0.17," it may be the update file only or a bundled version. If it's just the update, you must also have the "Base Game" installed for it to work. Nintendo Switch NSP Combination Install Tutorial
: Use a tool like WinRAR or 7-Zip . Right-click the first part ( .part1.rar ) and select "Extract Here." This will automatically pull data from all other parts to recreate the single, full .nsp file.
: Multi-part archives (like .part1.rar ) require every single piece (part2, part3, etc.) to be in the same folder before you can extract them.