The way to remove the watertank is to disassemble the rear grill and the curtain as shown in the manual assemblage nr. 2
At the bottom of the watertank you will see a knob/ handle.
Turn that knob/ handle on the watertank to the left as shown in the picture below.
Take the rear grille out off the back of the air cooler
Loosen this screw to disassemble the curtain bracket.
Disassemble the curtain from the bracket.
Pull out the tank
To assemble the watertank, follow these steps in reverse orde