try this link - the easy way
http://neighbors.designcommunity.com/notes/1229.html
The hard way (but not too hard)
Thin pieces of foam core or illustration board
and a hot glue gun.
Use an xacto-knife to cut the shapes out of the foam core.
(it cuts pretty easy)
If you have the time you can create
the detail by cutting out sections
from the tower/foam core to represent
the structure.
Use the hot glue gun to fix the 4 sides
together.
If that becomes too messy or you run
out of time either paint the detail (acrylic paint)
on the foam core or enlarge a good image
of the tower and paste it on the foam core.
You may have to build the top section
and bottom section separately and then
fit them together.
You will need a good side view of the tower.
Use this as your template for the model.
Good luck.