Thera a 5 steps on the ladder to success:
have the USB drivers loaded
recognice uSB device ad /dev/scsi ... Path
fdisk of this path to create partition on USB stick
mkfs.ext3 to make unix filesystem on this partition.
Mount the USB stick (automount, fstab,..)
Instead of finding out all these commands and then have troubles with each of them, you can use the multiboot disable feature to achive what you are looking for:
FTP the kit (8.3) to /var/tmp
and then type in telnet:
cd /
bunzip2 /var/tmp/multiboot*
tar -xvf multiboot*
/var/tmp/multiboot.sh disable u
After successfull execution USB stick should be formated and mounted empty at /media/usb.
Multiboot is not installed in this case, and after a reboot the kit will be gone from /var/tmp completely !
Instead you can off course simply use the enable u feature of multiboot and have the whole image copied to the USB stick (bootable !)
with /media/mb/multiboot.sh copy 1 after the enable ;-)