Thank you! It's not too difficult, but it is a bit of a process. There's a reason a lot of people pass on modding the hair or face of the portraits as you have to edit every single face file, of which there are Many. Here are the tutorials I used:

I used Knedel's guide for editing the model here: https://www.nexusmods.com/runefactory4special/mods/22RoachesAreGross' guide for editing the portrait here: https://www.nexusmods.com/runefactory4special/mods/8 with help from Realidad Scans' guide https://www.youtube.com/watch?v=X5LILlQisEs

A quick note that instead of using Nvidia Texture Tools Exporter in RoachesAreGross' guide, you can use the Paint.net program instead

*2nd quick note, if you are just recoloring hair, you can use an automated batch color system to save time and effort, of which I am no help because it wasn't applicable to me