This is a tutorial for newcomers to the Persona 5 modding scene, but it can also serve as a checklist or reminder for current modders. The area I'm covering is specifically for making sure the new model you bring into the game will work, it does not cover the process of fully rigging a model. What we want is to make sure the model is functional before starting heavy work like retexturing and rigging. You wouldn't want to put all that work into a model only to find out that its completely unusable and you have to scrap everything.
When bringing in models (usually from games outside Persona) to replace characters in Persona 5 (for example Michael Myers over Joker), it may not go so smoothly. There are chances you will experience errors in GFD Studio or have access violations/softlocks when loading the model in game. This walkthrough will make sure any model will work in game.