Via USB (DBI or NUT) or SD Card (exFAT), copy the Base NSP and the New Update NSP to your microSD:/install/ folder.
Go to System Settings → Data Management → Software. Delete any existing Saints Row IV Re-Elected update data. Do not delete the base game save file. saints row iv reelected switch nsp update new
If you are still running the launch-day version of the game on your modded Switch, you are missing out on the ultimate presidential power trip. Update now, cause mass chaos in the Oval Office, and as the Saints say: “Don’t fear the reaper... fear the next-gen patch.” Via USB (DBI or NUT) or SD Card