Board Thread:LotR Mod Technical Support/@comment-26184570-20170815204703/@comment-31507215-20170815211124

You have to go to your .minecraft folder (which can easily be accessed using the "Open Folder" button in the texture packs, and going up a few directories), find the profile that you use for the mod (which may just be the main folder), click the "mods" folder, and then replace the current mod file with the new one.