To perform a hard reset, use a pen, paperclip, or any pointed object. At the bottom of the equipment, you will see a small hole. Inside the hole, there is a reset button press and hold it for 20 seconds. You should feel a click when pressing the reset button, make sure you feel it to confirm the reset.

There is also an alternate option in the web based interface of the S33 where you can perform a soft reset 

Please refer to this link, where you can find the steps to perform both a soft and hard reset.

 http://arris.force.com/consumers/articles/General_FAQs/S33-Factory-Reset

what makes you think you need to reset it? 

Most modems are set and forget as there isn’t really anything to change on them. 

i rebooted mine from the router web page, i’m guessing you can reset it there also, i seen the reset icon right below the reboot icon

We don't have remote access to perform the reset on our end. You can use a paperclip to press and hold the reset button, ensuring you feel a clicking sound.

http://arris.force.com/consumers/articles/General_FAQs/S33-Factory-Reset