I saw people changing that upper balls with presing out old and hummering the new ones on menny cars. You can even go to youtube and see some pressing out

All they do is take of the arm measure the ball, go to some parts dealer and find same balls.
This last is litle problem because they ask you which balls do you need and if you tell them that you need upper they will tell you a 100 times that you can nott change upper ball so ask for lower wich could be close tp ypurs, measure it, if it is what you looking for buy it if not ask for another

untill you find one.
But if you thrashed ball in some crater on the street it is beter to change all with control arm an bushingss.