- Loosen the nut of the defective propeller with the 5.5 mm wrench.
- Lift the propeller carefully – without too much pressure downwards on the motor.

Note: There are two varieties of propellers (right- and left-spinning). The propeller direction is shown on the propeller by an arrow (see example for a right spinning propeller in the figure to the right).
- Check the propeller spin of the disconnected propeller.

- Align the new propeller with the correct propeller spin to fit onto the propeller mount.
- Press down the propeller completely on the mount.

- Put the new self-tightening nut onto the motor shaft.
- Hold the motor head with thumb and index finger of one hand to prevent the motor shaft from spinning.
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Tighten the nut with the 5.5 mm wrench.
- To do so, turn the screw-wrench with the index finger of the other hand. As soon as the motor head starts turning as well, sufficient force has been applied.

- Check if the propeller is spinning freely when you nudge it. Depending on the applied force, the propeller has to make several turns.
- Check once more the orientation of the propeller, and compare the movement with the other propellers!
