How do I descale the machine when the CLEAN/DESCALE light is solid?

Dissolve one Breville Descaling powder sachet into 34 fl. oz (1L) of water and fill the water tank. Press and hold the 2-CUP button and POWER button simultaneously to enter Descale mode. When ready, press the 1-CUP button to descale the coffee component (approximately 25 seconds), then turn the steam dial to descale steam and hot water components. Repeat the process until the solution is empty, then refill with fresh water and repeat to rinse thoroughly. (Page 25)