How do I apply a patch to a game that is already installed to my 2DS? (I bought it before I added cfw.)

[RequiemWasStolen]

Hey there. I'm trying to apply a PLG patch file to Fire Emblem Fates in order to add some fan translated Japan exclusive content.

I already have Fates installed on my CFW 2DS, I paid for the game and all the officially released DLC before I got CFW.

Is there a way to patch my copy with it?

 

[CoolMe]

Does this patch require the cia file? If so, you need to dump the game with GodMode9 to get a cia file, then you can patch it and install it again.
If this patch can be applied without the need of the cia file, there'd be patch files that should be placed inside sd:/Luma, with "Game patching" enabled in Luma3DS Menu..
One more thing to note is your save and extdata, you should back them up with Checkpoint, there's a possibility that they may not work with patch and you might end up corrupting your save..

 

[AmandaRose]

If this patch can be applied without the need of the cia file, there'd be patch files that should be placed inside sd:/Luma, with "Game patching" enabled in Luma3DS Menu..

It should actually be sd:/luma/titles but in saying that it's not always the case for instance the English patch for Rocket Slime 3DS goes in sd:/fti/rocket_slime_3ds.

 

[godreborn]

I think it will work without redoing everything. It should be sd:/luma/titles/title id. If not, try ntr cfw, that goes in sd:titles/title id though, but the first path should work. Romfs stuff and ips patches go in there as well, but @AmandaRose is correct that not all game patches read from there, but I can pretty much guarantee it will in that folder.