How do I perform a cleaning cycle when the CLEAN/DESCALE light flashes?

Insert the 1 CUP filter basket into the portafilter, followed by the cleaning disc and 1 cleaning tablet. Lock the portafilter into the group head with a large container beneath it, ensure the water tank is filled and drip tray is empty, press POWER off, then press 1 CUP and 2 CUP buttons simultaneously while also pressing POWER and hold for approximately 10 seconds. The cleaning cycle will last about 5 minutes with intermittent water flow, then sound 3 beeps when complete. (Page 24)