Back up any important files stored on the Chromebook
Sign out of your Chromebook
Turn off the Chromebook
Press and hold Esc + Refresh (the Refresh key is usually the circular arrow)
While holding Esc + Refresh, press and hold the Power button
Release the Power button when the recovery screen appears
Release Esc + Refresh when the recovery screen appears
Press Ctrl + D to turn on Developer Mode
When prompted, press Enter to confirm
Wait for the Chromebook to enable Developer Mode (it will reboot and wipe user data)
When the “OS verification is off” screen appears at startup, press Ctrl + D to boot
Enable any additional prompts to complete setup in Developer Mode