Reverting headset unlock

Download the Custom Resolution Utility (CRU) and run the reset-all.exe program included in the utility.

Reverting motion controllers unlock

Unpair (remove) the motion controller in the Bluetooth settings in Windows, then pair it again.

Clearing environment data

Open a File Explorer window, then type C:\ProgramData in the navigation bar. Note that this folder is typically hidden by Windows, therefore you must type in the full name to enter it.

Find the folder named WindowsHolographicDevices and delete it.

SteamVR

Uninstall the "Oasis Driver for Windows Mixed Reality". There are no global settings left after that.

Device Manager

If you disabled the Mixed Reality device manually, remember to re-enable it (same as below but click "Enable device" instead):