Back up any important files to Google Drive or an external device
Sign out of your Chromebook
Turn off the Chromebook
Press and hold Esc + Refresh, then press and hold Power
Release Power when the Chromebook turns on, then release Esc + Refresh when you see a recovery screen
Insert a USB recovery drive (created using another computer) into the Chromebook
Follow the on-screen prompts to reinstall ChromeOS
When complete, remove the USB recovery drive
Select your language and sign in with the owner account
If prompted, confirm the device name and complete setup
After setup, open Settings
Select Advanced
Select Reset settings
Select Powerwash
Confirm Powerwash and restart
Sign in and complete setup