you find the <titleID> for the Title you want to change here:
http://nswdb.com/
(use the search bar on in this case lookup
Nintendo Entertainment System)
You will see this one says 0100D870045B6000 under the titleID colum.
View attachment 331773
under sd:/atmosphere/contents/<titleID>/ you should see a
romfs folder.
In this specific case it would be sd:/atmosphere/contents/0100D870045B6000/
For now just move/rename it to something else (like romfs.bk).
Then restart the game and your mods should be gone.
If you want it back you can move/rename romfs.bk back to romfs and your mods should be back just like they were before we did anything.