With low rotor speed, lower collective to place the blades to low pitch. I don't believe X-Plane will support a demonstration of ground resonance. This can occur if you catch a skid on the ground and the aircraft will roll about it onto its side. The motion is extremely quick, and usually unrecoverable. You will just be unable to react fast enough.
Dynamic rollover can occur during a slope landing, or even if a skid ices to the surface.
The best way to get out of dynamic rollover is to just avoid it as you touch down or lift off. Check that the aircraft is free of the ground, or if skid icing is suspected, move the pedals slightly until you are sure you will break free. I don't believe X-Plane will support a demonstration of dynamic rollover. Mast Bumping Mast bumping is a condition that only occurs in teetering rotor systems. Although the rotor is still providing lift, it cannot provide control to the aircraft, which is free to move any way it chooses.