I think you are making mistake somewhere
Reset the router first. Press the reset button for a few seconds
Plug the computer to any of the router's LAN ports
do not plug the router to the modem now
Login to the router's page at http://192.168.1.1
leave the username blank/empty and the password is admin.
Go to the MAC Address Clone tab and enable it and clone the MAC and click save settings
Go back to the setup tab and change the router's LAN IP Address to 192.168.2.1 and save the settings.
Reboot the router first before you plug it to the modem.
This should definitely work