This technique applies to the steering tie rod ends on the MGA (and other cars). It can also apply to upper and lower suspension ball joints on other cars using that type of suspension.

DISASSEMBLING BALL-JOINT STUDS
You don't need a special tool to remove a ball-joint stud. Loosen the castellated nut several turns. Now all you need are two heavy ball-peen hammers of equal weight. Hold one hammer against the "ring" holding the ball joint stud, and strike the opposite side of the ring with the other hammer. Several hard blows should loosen the ball joint. Remove the castellated nut and take the stud out of its support.

This method is not only relatively easy; it does not damage the rubber grease boot, important if the ball joint is to be reused. Caution: When removing upper or lower suspension ball joints (not MGA), follow the manufacturer's instructions for compressing springs to avoid injury.