Hi,
To input changes you have to be netmanager.
you type se priv=net
then asks fior psswd
~I assume you don't know the psswd, therefore:
boot up the router or if already booted using a non conductive pin press the switch(located on left hand side, you'll see a round hole.
This gives you access to the you can say debug console,
type cl
and input ip addresses, mask when all done come back to main menu.
type xd
make sure your tftp server is running
type ?
gives you menu
type nb
router boots off network
enter router and type df
will show directory structure
fine file system
and type rf system
reboot
you will have no manager psswd or you can download the image again - if easier