format usbstick with ext2 and label it "Optware"
cd /opt
wget http://bin.entware.net/armv7sf-k3.2/installer/generic.sh
chmod +x generic.sh
opkg update && opkg upgrade
opkg install avahi-autoipd 0.7-2 avahi-dbus-daemon avahi-dnsconfd 0.7-2 avahi-utils 0.7-2 libavahi-client 0.7-2 libavahi-dbus-support 0.7-2
The Final Step is to add the following commands to the start-up script (Administration tab - then Commands). The sleep value can be adjusted, but 10 is long enough for most USB Harddrives/routers:
echo "nogroup:x:114:nobody" >> /etc/group
echo "nobody:*:114:114:avahi:/opt/sbin/avahi-daemon:/bin/false" >> /etc/passwd
sleep 10
/opt/etc/init.d/rc.unslung start
avahi-daemon &
reboot router