XRAY - Model racing cars

Hi i just got my first x ray it's a t4 2014 used so I didn't build it and I wanna switch spur gears does anybody know how?

Thanks

remove top deck,undo the 2 screws under the chassis that hold the right layshaft bulkhead in place,remove bulkhead,remove spurgear ,to put back do this in reverse
once out the belt pulley just pulls off ,the adaptor has three screws in it remove these and the pin,slide off spur and replace with new one same to put back

Ok thanks so much