Fortress Maximus Custom

Hey, I'm doing a custom Fortress Maximus out of an Armada Unicron, and after seeing this one out of a Cybertron/Galaxy Metroplex, the one thing I'm struggling with is how to do his side-ramps. Corvus seems to have made a great pair, so I was wondering if any of you guys could give me any tips of how to make these or similar ramps?

Go here to see the Fortress Maximus Custom I'm talking about
http://www.actionfigurecustoms.com/2007/12/05/custom-transformers-fortre...