Someone did a conversion a while back, let me see...
*tap tap tap*
ah, here we go:
http://www.rc-monster.com/forum/showthread.php?t=12679
Wow, cant believe that was 2 years ago- was a great project to follow. Generally speaking a basic L-shaped motor mount would be the simplest option- could probably adapt the revo motor mount Mike ( our Lord & master ) sells in the rc-monster online shop, depends what tools you have to hand ( vice, hacksaw, bench drill and some files should do nicely ).
Welcome to rc-monster, home of some very odd people- hope you have a good sense of humour