AndyMark CIMple Box CAD help

I'm trying to use the AndyMark CIMple Box for a CAD design, but I'm having a slight problem - The assembly I've downloaded from the AndyMark website has not mates on it, and the pieces rip apart when I try and move the assembly. Is there any way to fix this? Is there any other CAD of the CIMple Box gearbox where the parts are all properly mated? I'm using the student edition of Solidworks 2012-2013, if that makes any difference.

Thanks!