Unscrew the brass cylinder on the bottom of the assembly, the one with the hole on the side: insert a small screw driver into the hole and turn the cylinder counterclockwise- that will release the whole capsule from the mount (the black plastic surrounding the capsule's perimeter is part of the capsule, do not attempt to separate it!
The round plastic nipple on the top is only lightly glued on, so that will come off without a hitch.
But I am wondering what comes next?
MG does not sell these capsules separately, but the company's capsule replacement service is reasonably priced.
On the other hand, M7 reskins from third parties are notoriously unsatisfactory in sound.