The siphon should work to remove all of the water from your boiler. Repeat this on the other boiler. Note You need to ensure the end of your tubing gets to the bottom of the steam boiler as it can easily hit the heating element and stop.

Tip: You can use a bamboo skewer or similar to straighten out the tubing and run some very hot water over it for a minute. It should stay straight enough after that to work great!

If you've gotten to everything out of the steam boiler, you should have some murky, scaly water. Using your flashlight in one of the ports, you should be able to see if you've emptied the boilers.

Now place your funnel in one of the ports, and carefully pour descaler into each boiler until just about full. The steam boiler is about 1.5L and the brew boiler is .5L.

Now you have an option - You can let the descaler do its job and wait, or you can replace your probes and wires, turn on the machine to heat it up and carefully run descaler through the steam wand, group head and hot water valve. You just need enough to saturate the paths and sit. Turn off the machine

Wait 30 minutes or so. Repeat the siphoning process for both boilers. You should hopefully see the solution is discolored (it depends on the descaler). Check the condition of the boiler elements with your flashlight. You may want to pour new descaler into the boiler if they're not quite sparkling. Heat it in the microwave first.

Once you're satisfied with the state of your boilers (it may take several drainings depending on scale), drain a final time, and refill both boilers with clean water. You can be extra and used distilled if you want. You'll need to drain and fill a couple of times here as well. You just want all of the descaler rinsed out.

Fill each boiler about half way - we still need to clear the water path prior to the boilers in the next step. Replace the probes and wiring and turn the machine back on. If you didn't perform the optional cold water path descale, you can skip to the final rinse!