Tearing down the rotor assembly is very easy to do. The diagram of parts in the back of your manual will be quite helpful! As for your wobble, I would start by making sure the flybar is nice and straight and that the weights are pulled out to the ends of the bar. Next move on to removing the inner shaft and rolling it on the edge of a table to check for wobble. It's really easy to bend just the tip of the inner shaft. Even the slightest bend will cause wobble. If that checks out move on to the outer "main" shaft and repeat the rolling test. Unless the swashplate is blown (unlikely), it's gonna be one of those 3 things causing the wobble. I wouldn't continue flying any bird that has a head wobble, as head speed increases it's only going to get worse and worse. It's not as big of a deal on these coaxial birds, but on a collective pitch heli bends are baaaaad, wobbles = death.