FTTH 1GE Micro Mini 1.25Gbps xPON ONU G125X

[qatar2030]

dear all
i just bought FTTH 1GE Micro Mini 1.25Gbps xPON ONU G125X and i do:

1.download putty/securecrt
2.telnet 192.168.1.1
account: root
password: Pon521
3.sismac 1 2176 xxxx (Modify Vendor name,4 characters)
sismac 1 2177 xxxxxxxx(Modify the last 8 digits of SN,8 characters)
sismac 1 2183 xxxxxxxxxxxx(Modify Model name)
4. reboot
Please replace xxxx with the number or letter you want to modify yourself.
( this is what company seller give it to me)
but i couldn't change
Hardware Version to 16ED
is there any help please?
regards