are you asking what to do with a 3-dimensional vector that represents a 2D coordinate in homogeneous coordinates?
if you have a vector, the last dimension is the projective one. you take that value and divide the entire vector by that.
(xw, yw, w) / w = (x, y, 1)
and that’s it.
please find a book or other teaching materials that explain this to you.
if you have questions based on that, feel free to ask.