Press and hold Escape and Reload, and then press the power button
That should bring you to a screen that instructs you to enter in a usb drive
Press CTRL + D at that screen
That should bring you to a screen that asks to turn on OS verification
Press Enter at that screen
The display will go dark and come back to another screen that says OS verification is Off
Press Space or Enter, whichever it is asking you to turn on verification
The computer will reboot
After it turns on, connect it to a WiFi network
Login with a faculty district email account to re-enroll the device