There are clear instructions in the manual for the drives complete with photos for installation in the 2x40 crocodiles and 2x45 box cabs. There is also a full size pattern for laying out the slots that need to be cut in the roof. The manual used to be downloadable from the Massoth website and I intended to include a link but the latest Massoth website "update" appears to have eliminated all the links to
any of their manuals.

I checked both the English and German versions of the website. Probably some bean counters better idea

but a terrible move on the part of Massoth. Nobody I know would buy anything DCC related costing more than a few bucks without being able to view the manuals before hand.
I've got a copy. PM me.