He doesn’t actually know that ritual, though. Quirrell does stuff with his wand and Harry knows better than to just blindly copy whatever off his memory.
The resurrection ritual, as near as I can tell, requires only going to that obelisk, placing flesh on the slab, and saying “X, X, X so wisely hidden”, where “X” is whatever you you have—blood, flesh, bone, vitreous humors of the eye, whatever.
He doesn’t actually know that ritual, though. Quirrell does stuff with his wand and Harry knows better than to just blindly copy whatever off his memory.
The resurrection ritual, as near as I can tell, requires only going to that obelisk, placing flesh on the slab, and saying “X, X, X so wisely hidden”, where “X” is whatever you you have—blood, flesh, bone, vitreous humors of the eye, whatever.