You can make a spring removal tool out of a piece of square tubing. It has a cut-out on the end to slip over the ball stud and a cut-out in the center to allow access to remove the spring lock keys. Real simple and works great if one is just doing seals with the head still on.
I will see if I can list the dimensions... or.....just get a Hayne Manual and they have a picture of one and how to make it...
I use a magnet to grab the keepers.
Make sure you get the new style seals.