This may be more information than you are looking for, but.
1. You must determine what default IP address the Obi is using before you start.
2. Disconnect your computer from your network / router and set a static IP address into it that is one away from what the Obi is using. I.E., if the Obi is 192.168.10.1 then set your computer to 192.168.10.2
3.Disconnect all of the ethernet cables from the Obi. Next, connect your computer directly to one of the Lan ports using a standard crossover cable. You may need to purchase one.
4. Point your browser to 192.168.10.1 and you should be in and able to do anything you need to.
This is the way to always be able to access any device and configure what ever you need to. Just remember If you need to change the IP address of the Obi, make it the last thing you change because once you change it, you won't be able to access it any more unless you change your computer IP again.
*edited* since the 202 is designed as a router you may not need to use a crossover cable. Try a standard ethernet cable first.