You won't find many pictures simply because its a straightforward process - place the engine inside the frame, make sure the sprockets are aligned properly, mark your holes and drill. Although the process is straighforward, it is a pain in the ass and is very time comsuming, especially if you don't have the right tools.
Most people on this forum don't bother with the headache because
cjtmini offers an aluminum adapter plate as part of a complete engine mounting kit. The price is cheaper than drilling out the holes and trying to fabricate everything yourself. It looks good and requires no cutting or drilling.
Here is the link for the entire kit, but I think he'll sell individual pieces. I'm not sure what the adapter plate itself goes for, but it'll be cheaper than the labour it will take you to drill out the holes yourself.
http://www.oldminibikes.com/forum/b...bikes/10349-db-30-6-5hp-engine-kit-parts.html