the gasket is 2 parts the large rubber part and the small rope part I did it without the proper tool and it was not that bad.
I had another one done by the glass place and they had the proper tool and it only took them a few mins per window.
It is the same gasket as the little rear side windows you already removed.
You may want to buy new gaskets they are not too bad.
it will be a good skill for the students to learn