Turn off the Keurig and unplug it
Remove the water reservoir and empty it
Refill the reservoir with fresh water
Plug the machine back in and turn it on
Run several brew cycles with water only
Press and hold the 8 oz and 10 oz buttons together for 3 seconds
Release the buttons when the descale light turns off
If that does not work, power off the machine, then repeat the reset steps
If the light stays on, run another full rinse cycle and try again