@SteelDuck You have to have a software like photoshop or clip studio paint.
(Example is for body textures but it's the same exact process for the face textures)
Personally I use clip studio paint, firstly you need to throw the PSD file into the program (the file will all the layers) then open a new tab in the art software. Next import your original base body texture, then copy the layer. Go to the tab with your PSD of Milky Way and paste the original base body texture on the bottom layer so all the extra layers are overlaying it. Lastly export the texture as a PNG and import it into your project and just replace the base body texture, then select the mask for the corresponding texture (really easy to do in Liltoon shader). You should be all set!
Hopefully this helps, upvotes are appreciated, sharing is caring
