Because this is a multi-part RAR file, you cannot simply use Part 2 on its own. To access the update, follow these steps:
Right-click on Part 1 and select "Extract Here" using software like WinRAR or 7-Zip. The software will automatically "stitch" Part 2 and the others together to produce a single .nsp file.
Once extracted, you should see a file ending in .nsp . This is the actual update data for FC 25 . How to Install the Update on Nintendo Switch
This confirms the file is an "Update" package for the Nintendo Switch (NSP format).
Always ensure you are sourcing files from reputable places to avoid malware, and remember that modifying game files should only be done on systems where you have full ownership and authorization to do so.