If you want to clean the water tank, press the release button and take the water tank out of the appliance. Open the lid and remove the anti-spill cover. Rinse the water tank under the tap.
If the water tank needs a through clean, you can use a washing-up brush and some washing up liquid. In that case, make sure you rinse the water tank thoroughly with clean water afterwards.
Do not forget to put back the anti-spill cover and the lid before you reinsert the water tank into the appliance.