You’ll have to do it from the command line, of course.
1 - SSH into your BBB
2 - Follow the instructions at http://kb.roonlabs.com/LinuxInstall (in the page search for: The Easy Installer (Recommended) ). In that section follow the instructions for RoonBridge armv7hf (it’s just 3 lines that you’ll have to copy and paste into your BBB command line and execute)
3 - See if your BBB shows up as a networked Roon Bridge in Roon. If it does, and you can also see your DAC there, you’re finished.
4 - If it doesn’t you may have an old glibc version like me. Go to /opt/RoonBridge/ on the BBB and try starting RoonBridge manually: ./start.sh If you get an error saying roon needs glibc version 2.14 it means yours is older than that. Follow instructions at http://stackoverflow.com/questions/19471683/lib-libc-so-6-version-glibc-2-17-not-found (last reply, the one from InvictusRex28). After upgrading glibc try starting RoonBridge manually again. It should work and the BBB should appear as a zone in Roon Server.
If you need any extra help, post here and I’ll try to guide you better on any of these steps.