activating new modem

I'm super confused by this process.

I'm going to be getting a new modem, and in reading up on the modem, it says disconnect old modem, attach coaxial wire, plug in power wire and let modem go through power cycle.  Attach ethernet cable and plug into a laptop or other computer and activtate using the activation link.  Seems simple enough.

Here's the sticky wicket.  the instructions say, the modem is not activated, so no internet access will be allowed.  

Question is....how do you activtate it through a website if it's not activated?  The objective is to avoid calling Xfinity as the automated menu's just stink and getting a live person is more difficult than it needs to be and it took them 8 hours to activate my old modem.