Hey, super cool that your'e getting married at the ruins. It is stunning.
So...just to clarify, you want to enter from the monastery's main entrance? and have stairs that come down from the doorway to the bottom for the ceremony?
I'm not sure how you're going to achieve that to be honest. I know the space pretty well as I worked worked with Shakespeare in the Ruins there this past summer (they do Shakespeare productions at the ruins every year). You can't enter from that main doorway with that fence there, even if you had stairs going down form it.
BUT...I would actually suggest reaching out to Shakespeare in the Ruins. They know the space better than anybody and have used it in MANY configurations.