Unless you're being asked to range the modem by a service tech via the phone, you shouldn't be doing it. There are specific parameters that need to be used for the particular satellite you're trying to access. Don't be surprised if you will need to pay for a service visit if you mess it up.
* Disclaimer: I am a HughesNet customer and not a HughesNet employee. All of my comments are my own and do not necessarily represent HughesNet in any way.