How do I make a simple texture patch for a 3DS game (Luma Title Patching)?

[retrospect]

At first I just want to swap the texture for the Hylian Shield in Ocarina of Time 3D. The texture they shipped has a stretched Triforce and it looks poor imo. I'm surprised it wasn't fixed in an update.

There's a replacement online (.png format) but it says it's for Citra.

I thought there might be a way to tell Luma to use one RomFs to patch another.

 

[retrospect]

Hurray, it's called LayeredFS and it sounds easy.

 

[smurgburglar]

Hurray, it's called LayeredFS and it sounds easy.

Did you ever get it to work?
I have no idea what to do.

 

[retrospect]

Did you ever get it to work?
I have no idea what to do.

I'm not sure if I got it working for Majora's Mask.

I think I got LayeredFS working for OoT and I didn't like the changes overall. It was a package deal and it changed a lot, and customising it turned out to be harder than I'd expected.