After intensive research and trying several methods. I write here.
I cannot for the love of Cthulhu open the tank to refill. It's not moving! I'm a very beefy guy, but nothing. I cannot open the damn thing. It's really frustrating.
And I already tried that thing:
We suggest the use of soft lint free gloves or cloth, much like those used to clean eye-glasses, to help with the disassembly so that you do not scratch the glass tank.
First screw the upper hardware tightly,then unscrew the base hardware.