CF21-BL: Updated getting-started motor mount section and removed prop…

… balancing

src/documentation/tutorials/getting-started-with-crazyflie-brushless.md

@@ -53,11 +53,7 @@ Start by unpacking the box. It should contain the following items:
 
 {% endsi_step %}
 {% si_step mount the motors %}
-Push the four motors into the motor mounts. You will need some force to
-insert them. If it is difficult doing it as in the video try putting the
-motor can towards a table edge and press on the mount. However, don’t press
-on the motor axis while inserting them as it might damage the motor. The
-motor should be inserted all the way to the stop in the mount.
+Position the motor above the mounting holes, the motor cable should run along the arm. Use 3 black screws in the corner holes of the motor to fasten it. There is a screwdriver in the kit you can use to fasten it.
 {% tutorialVideo /videos/screwing_motors.mp4 %}
 
 Attach the motor cables to their connectors and twist the wire 180 degrees to attach to the connector. 
@@ -329,15 +325,6 @@ To avoid this, particularly when learning to fly, use a lot of thrust just
 when taking off and then ease off for level flight.
 {% endsi_step %}
 
-{% si_step if the Crazyflie is unbalanced; unbalanced %}
-If your Crazyflie drifts a lot when taking off, there are a few things you should check.
-
-* Make sure the battery is centered. If it has slipped
-too far to either side, the Crazyflie might have a hard time
-compensating for it.
-* Check that the propellers are balanced, {% id_link balancing-propellers %}
-{% endsi_step %}
-
 {% si_step charging the battery; charging %}
 To charge the battery of the Crazyflie, just plug in a micro USB cable. Make
 sure the Crazyflie is powered on. While the battery is charging, the back left