If you don't want to remove your SD card, use on PC and Awoo Installer on the Switch. Connect via USB-C cable to install the NSP directly.
Assuming you have a hackable Switch (unpatched Erista model or a modded Mariko/Lite with a modchip) and have setup custom firmware (CFW) like Atmosphere, follow these steps: Go Vacation Switch NSP
The search for highlights a desire for accessible, offline, couch co-op gaming. While the technical process of installing an NSP is straightforward for those with hacked Switches, the legal and ethical implications are severe. Nintendo is notoriously aggressive with lawsuits and console bans. If you don't want to remove your SD
If you cannot find a reliable NSP or want to avoid modding, consider these legal alternatives on the eShop: While the technical process of installing an NSP
The Switch version includes several quality-of-life updates and exclusive content compared to the original Wii release: