Cant be done. Its impossible. The game has integrity checks so even if you do mod you HP, stamina and Ichor the game will simply reset it to default every time you start it. There's no way to bypass it.
Unlike God Eater 3 weapons cannot be modded either. The game crashes once you load your save.
On top of that, the save structure moves around every time you save. Test it yourself. Its too hard to do things right. You can literally compare 2 saves with no changes between them at all, simply saved after each other in HxD and you'll find hundreds of differences where there should be none. That's why the other codes don't work.
Give up on this game.