You will have to Export them as .DXF or .dwg files from AutoCAD. Maya can import these file types. But I'm not sure how well it will import certain data types (Surface data) It may have to be a specific data type (Recognized). Like Nurbs.
Just do a Google search.
"Your weapons are no match for ours! People of Mars, surrender!"
"Um, this isn't Mars. This is Earth."
"Earth? Earth-with-nuclear-weapons Earth?"
[long pause] "Friend!!"