A detailed description how to create .dsnd files using BFD2 can be found in BFD2toDSND.pdf. This description has been written by Brian-D (Haggis-man) from the unofficial 2box forum, and put on this site with his kind permission.
The midi file referred to in the description can be created with DSoundTool as described here.
Also "Slap the Drummer", "JMan" and others have described some tips on the unofficial 2box forum in this thread.
On http://www.2box-forum.com/resources/ there is some information from FXPansion on using BFD2 samples in 2box modules. Here you can read ("us" = FXPansion):
"You can legally import BFD (1+2+expansions) samples from your own BFD2 in to your own 2box brain - however you cannot legally distribute them, even to others that own BFD2 and a 2box brain. If you or somebody else does make some 2box kits from BFD2 samples, would be good if you can send them to us - we can then redistribute them to other 2box + BFD2 owners on request."