IMPORTANT:
Be sure to disconnect the unit from the power supply before replacing it.
STEP1:
Remove the plastic front cover from the device (it is only attached by magnets at the 4 corners = so you don't need to use any tools)
STEP2:
Very gently slide out the cover with the beaker cuvette into which liquids from the droppers fall (this is only inserted in the plastic groove = here too therefore you do not need to use any tools).
STEP3:
Using a gentle motion, grab the first dropper, i.e. the middle one that is closest to you, and slide it out in a slow upward motion so that it fully slides out into the lower and upper clamp/clamp. (It is easiest to hold the dropper by the transparent cap when lifting it).
STEP4:
Analogous to step number 1, proceed with the other two droppers (rear left and right). The order in which they are lifted from the clamps and removed does not matter).
STEP5:
Now, holding the transparent cap firmly in one hand, grab the pink part of the dropper and unscrew it from the cap (i.e. counterclockwise). They may be tightly twisted - this depends on the force used to screw them on earlier).
STEP6:
Analogously to step number 5, proceed with the other two droppers (rear left and right). The order in which they are unscrewed does not matter).
STEP7:
Screw the new dropper into the transparent cap also holding it by the pink part so that it tightens differently and completely (by twisting in the other direction = clockwise this time).
IMPORTANT: do not hold the needle while tightening to avoid damaging or bending it.
STEP8:
Analogously to step number 7, proceed with the other two droppers (rear left and right). The order in which they are screwed in does not matter).
STEP9:
Now place either of the rear droppers (left or right) already screwed into the nut back into the clamps/clamps by sliding it very gently upwards until it reaches the end.
A very important aspect is how to insert the dropper into the clamps:
(a) note that each dropper has symmetrically positioned tabs (wings) on both sides;
b) when inserting the dropper from above, they must be positioned perfectly on both sides (left and right) in relation to the rear wall of the unit, i.e. horizontally (and not vertically)
c) make sure that the dropper has slipped through both clamps and has pressed down firmly on the profiled bottom
d) make sure that the needle is not bent while inserting the dropper.
STEP10:
Analogous to step number 10, insert the other two droppers respectively - first the second rear dropper and then the middle (front) dropper
STEP11:
You are now ready to assemble the unit. Slide in the cover with the beaker cuvette (and the cartridges if they were also removable).
STEP12:
Fit the front cover of the unit.