heres what i do to change my ip
start
run
cmd
type ipconfig/release
an icon on your program tray or whatever in your lower right side.
click it
alternately you can go to start, control panel, "network and internet" options or whatever
click network connections
click your network that you use
click properties
click internet protocol (TP/ip) or whatever
click the box use the following ip and spam 1 and 2, at the end hit tab so it gives you a subnet
click ok
click ok and it'll pause for a min, then go back to it and click automatically get an IP, this resets the ip.
if using a router, plug directly into the moden during this and plug back into the router afterwards.
this should be easy, takes me 5 minutes tops.
works with PC's not sure with macs...