This tutorial is pretty old, but it may get you where you want to go:
http://southquarter.com/dromed/?p=17
Also, Dark Arrow's site has a zip file that contains all the resources needed to bring over burricks, bugbeasts, craymen, and fire elementals.
http://koti.mbnet.fi/~darkar/
And all that stuff is also available in the DEDX package.
http://www.thiefmissions.com/tools/