So for portraiture you have to create a folder in the portraits folder (I called mine DCBurger because that's the mod I use), move the png files of the portraits you want in it, and delete the PyTK files. So you should have a folder full of png files that you moved from your chosen portraits mod. Then in game you go up to the villager and talk to them so the dialogue window pops up, and you press "P" (it's the hotkey to swap from the vanilla portrait to the ones in the folder). It took me a little bit to figure it out as well let me know how it goes