I spend a good few hours working this out. I have been a long fan of Backtrack, and was unable to get it to work on the HTC DNA reliably until now. Here are the modified scripts.
YOU MUST BE ROOTED AND HAVE BUSYBOX FOR THIS TO WORK, I RUN DSB'S KERNEL AND UKB, WORKS FINE FOR ME. I TAKE NO RESPONSIBILITY FOR THESE INSTRUCTIONS OR SCRIPTS ON YOUR PHONE, USE AT YOUR OWN RISK.
bootbt - starts up the loop device, and mounts all the needed partitions
ubt - unmounts the partitions, and sets your path variable back to normal
Download the ARM img file from the main part of the site, Copy the bt5.img and other files (EXCEPT the bootbt) onto your sdcard into a folder named bt5.
Open terminal emulator and type su. cd to /sdcard/bt5 and type sh bootbt. Profit.
The bt image file is about 4.9 gigabytes. Technically it doesn't need to be that large, as the file structure is only about 2.5 gigs of space in use. If you want to resize it, you need to open up a Linux based VM (or like I did, Backtrack) or be on a linux machine and do the following terminal commands as root. (IE Sudo/SU)
This will create a blank image file that is about 3.2 gigs with 1 meg blocks
This will create an ext file system for said image, make sure to say yes when it warns about being a special block.
dd if=/dev/zero of=/path/to/new/btsmall.img bs=1m count=3300
This will create mounts to open the two image files
mkfs.ext4 /path/to/new/btsmall.img -N 35000
This will mount the two files, then copy one into the other, recursively
sudo mkdir /mnt/btlarge
sudo mkdir /mnt/btsmall
Once they are done, unmount
mount -o loop /path/to/large/bt5.img /mnt/btlarge
mount -o loop /path/to/small/bt5.img /mnt/btsmall
cp -Rfpv /mnt/btlarge/* /mnt/btsmall/
From there, copy over to your storage and make sure the file path reads /sdcard/bt5/bt5.img as that's what the scripts are meant to read.
Hopefully someone finds this helpful! :-)