If you’re selling or giving your Xbox away, or you just don’t want to participate anymore, before you sell or gift it to someone else, you should remove it from the update preview program. If you’ve already sold or gifted your Xbox, you can launch the Xbox Insider Hub on another console or on a Windows 10 PC and follow these same directions.
Note: This process typically takes about 10 minutes to complete. It might help to know the serial number or name of your previous console to ensure you remove the correct one.
As part of the removal process, your Xbox may undergo a factory refresh. If a factory refresh is required, your games and apps won’t be erased, but any profiles or system settings saved to the console will need to be restored after the refresh is complete.
Would you like to contact Support regarding the "How to leave the Xbox One update preview program" issue you were reading about or a different issue?