From ttmcmurry's post:
After spending way too much time on this and finding several failed solutions, I finally found a way to get rid of the Bittorrent client:
**These instructions assume you have ffp 0.5 correctly installed**
1) login as root
2) cd to /mnt/HD_a2 -or- /mnt/HD_a4 (depending on your setup)
3) type "rm -rf /Nas_Prog"
4) type "ls -l" to see if the folder deleted
5) reboot the 323
6) log into the download area of the gui
7) click on the bittorrent tab, you should receive a message stating "to install bittorrent..."
ffp: http://www.inreto.de/dns323/fun-plug/0.5/fun_plug.tgz