Cannot connect to the setup page

[Bonitablanca]

Hello there I was trying to access the set up page at 192.168.1.254 as suggested by billion and a number of other variations of this number but only get an offline "this pages is not available" error.
I am trying to change my settings to suit the new simcard I have purchased.
Help please cleaver people

[7800nUser]

Set the network address manually to 192.168.1.100, subnet 255.255.255.0 and then you should be able to access the modem/router's setup page on 192.168.1.254