How to Factory Reset Google Pixel and Pixel XL with Hardware Keys
If you find that the touchscreen is unresponsive, there’s a problem accessing the menu, or maybe you forgot your pattern lock, then you can still factory reset your Pixel and Pixel XL using the hardware keys.
Step 1. Turn off the Pixel or Pixel XL.
Step 2. Press and hold the Volume up button, the Homebutton, and the Power button at the same time until you see the Android icon.
Step 3. Using the Volume downselect wipe data/factory reset option and press the Power button to select it.
Step 4. Using the Volume downhighlight Yes – delete all user data and press Power to select it.
Step 5. After the Pixel or Pixel XL has rebooted, then use the Power button to select it.
Step 6. When the Pixel or Pixel XL restarts, everything will be wiped and will be ready to set up again.