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.