Turn the wheel into the position shown.
Take apart both parts.
Push back the hook and position the copper tube between the hook and the wheel.
Place the bending-side, justified by the plastic brick, on the tube.
Hook the bending-side into the stud in the middle of the wheel.
Spread apart both sides.
By pressing together both sides the tube is bent.
By spreading both sides again the ratchet clicks into another position.
Bending the tube in smaller steps will require less strength.
On the lower edge of the bending-side you can read out the generated angle of bend.
Once the required angle is reached, open up the ratchet and remove the tube.
Pressed again, the wheel assumes its neutral position.