@mismi,
He could do it in the form of a recipe and ingredients shopping list. To do this, he'll have to learn all he can about the physical properties of the wall and what it took to build it.
He'll have to determine what the ingredients are, how much will be needed to build how many miles of wall, and how much they cost in today's economy.
Once he has that, he can then develop a recipe card with the ingredients list, shopping list and procedure for building the wall.
Examples of the procedure could include obtaining the land, recruiting the manpower, engineers and supervisors. Gathering the materials and using them in a specific order would be the next steps.
For extra credit and his class presentation, he could make a small model of it with clay or plaster of Paris and do it in the style of a cooking show.