It looks like you’re referring to a NSP update (likely for a Nintendo Switch game) and a filename like dodonpachi resurrection nspupdate 104rar new.
What is Dodonpachi Resurrection?
I need to mention the necessary tools: RAR Extractor, Tinfoil or Goldleaf for installation, and a USB cable. Also, the Switch must be on firmware 10.4.0 for the update 104RAR. Maybe the user is on an older firmware and needs to update their system, but that's a gray area. I should mention the risks of using homebrew and the importance of backing up personal data.