First off I measured the brass bearings with some calipers to determine their size, the closest match is a 2x5x2mm bearing which i ordered from here. You require 8 bearings to replace all of the brass ones.
On the left is the ball bearing and the right the original brass bearing.
Step 1 - Remove prop, gear, rotor shaft. To do this there is a guide on the parrot website but essentially all you have to do is remove the circlip on top of the prop with a screw driver and slide out the rotor shaft. Be careful not to fire the circlip across the room as theyre tiny and easily lost.
Step 2 - Remove brass bearing. The easiest way to do this is to take the rotor shaft that was removed and insert it a few millimetres into the bearing, deep enough so that the tip should be past the base of the brass inside the mount. Then gently and slowly rock the bearing whilst pulling upwards until it frees itself. Be patient and careful to avoid damaging the plastic around the bearing.
Step 3 - Insert ball bearing. This can simply be done by inserting the ball bearing and pushing it home with your finger.
Here is the fully inserted bearing
Step 4 - Repeat the process on the underside bearing.
Step 5 - Reassemble the rotor, just reverse the process of taking it apart.
With one rotor done repeat the process for all 4 and you should be set with improved bearings. I hope this helps anyone who wants to do the same, but I must state that this will invalidate your warranty (although putting back the brass bearings is easy enough
) and you may damage your drone in the process, therefore I take no responsibility for anyone following this guide.Feel free to post this to the main site if you feel its worthy Symon.