1. Gently lay the Aarke Carbonator on its side on a hard surface.
2. Through the hole in the bottom of the machine, slide in the cylinder and, while still holding it, push it to the top of the opening.
3. When you feel it reach the top, screw the cylinder in with a clockwise motion until fastened, no need to over-tighten.
4. Save the plastic cap of the cylinder to put it back on and exchange when it's empty.