I would like to change my IP adress,

So i have a E1200 and im trying to change my Ip adress, not my LAN or WLAN Ip adress. I mean that IP adress : http://ipchicken.com/

Im currently using DHCP, i can change it.

I installed Putty, but i cant make it to work, you can explain to me how to settup putty so i just have to enter a couple of commands to reset my ip adress( I THINK). 

i Didn't pass the cisco certification test thats why im asking.