mkdir /mnt/sda1  (ignore the error if it tells you it already exists)
mount /dev/sda1 /mnt/sda1

If you want to mount drive F:

mkdir /mnt/hda55 (again ignoring the error if it tells you it already exists)
mount -t fatx /dev/hda55 /mnt/hda55

When finished you can unmount:

umount /dev/hda55
umount /dev/sda1

If your USB drive has multiple partitions, adjust sda1 for sda2, etc., as necessary.

Now that the drives are mounted you can either do the file copying via the command line using cd, cp, ls, mkdir, mv, etc.
or you can use the graphical file explorer emel:

emelfm /mnt/sda1  (would open emel file manager with /mnt/sda1 already open)

Or you can open both /mnt/sda1 and /mnt/hda55 in emelfm at the same time:

emelfm /mnt/sda1 /mnt/hda55  (opens emel file manager with both drives already open)

The other XBox partitions are available as hda50 through hda55 (e.g. hda52).  If you have a drive G: it might be 
at hda56, but I'm not sure about that.

Be sure to unmount all the drives before turning the Xbox off or rebooting, especially if you copied files.  Unmounting 
will ensure all files are copied and all buffers are flushed.  I find the best way to reboot is via the terminal as 
root using:

reboot -f
