If you prefer a direct "install and play" approach without pre-merging on a PC, is the most reliable tool available.
An MTP responder and homebrew installer for modified Switch consoles, recommended for dumping currently installed updates and DLC from a console to an SD card. Switch Army Knife (SAK) tools up rom nsp update dlc switch game updated
Here is your guide to the current state of Tools Up! on the Nintendo Switch, including what the updates and DLC actually add. If you prefer a direct "install and play"