I have just received a pair of SE180 motors. In order to access the mounting screws I have to remove the two plastic gears - I can remove the first (upper rotors) gear easily, but how do I remove the second gear (lower rotors)? I don't want to force anything that I'm not supposed to and have something break. Do I need to loosen the outer shaft retaining collar? Because I lossened the screw and it does not move.

I also received a microheli tailboom kit. However I can not install it properly because the M2x10mm cap screw will not screw into the frame as it is a much finer pitched thread than the original screw, and the 2x4x3mm spacer is too long to fit in the space between the boom's mounting bracket and the servo mounting flange. Has anyone else encountered this? It seems so straight forward, I'm not sure how I could be doing anything wrong!

Please help, I would like to get this flying again soon!

Thanks