If you have an Xfinity modem, you can reset it without the app. This tutorial shows you how ... Here's how to find it on your ...

How to change your Xfinity Wi-Fi password using the Xfinity app The easiest way to change your router password and router ...

If you go that route, Comcast will ship you a Getting Started kit with your equipment, and you'll need to follow the instructions in the Xfinity app to get everything up and running on your own.