The Botton above the lowest drawer has a heating foil. Unscrew on the back a PH2 Head screw. Also is a PH2 in front left at the Filter's place. Now carefully lift the Bottom. Take out the Styroporfoam-Element. Then open the Plasticbag which contains the Connector for the Heating. You should cut-off the AC-Mains before unplugging this Connector.

Now you can remove the Heating; Top of the Bottom.

Open the shorter PH2 Screw to release the LED-Light on the Bottom. That's necessary because with the wires at it you could not pull out the chassis of the Bottom.

Now you can pull out the Chassis of the lower Bottom, use a Plastictool for the Clipse. Pull off the holder of the Waterfilter.