The solution presented is correct, but not very clear. To get to the "leave" option:
1) press ALT+R to get the overlay
2) select the Settings icon (the gear shape), upper right of the screen
3) select the GENERAL option (at the end of the 2nd line of options)
4) scroll down to the "AMD User Experience Program" setting
5) select "leave"
6) press ALT+R again to close the overlay