You basically just remove them with a self made valve tool consisting of a c-clamp with a piece of tubing welded on the rod. The piece of rod should have a 'window' cut, or ground into it to allow you to pull out the keepers. You basically want to just put the one end of the clamp on the bottom of the valve and the other end at the top of the spring retainers, and then compress it just far enough for the two pieces to fall out. Once the springs and valves are pulled out you will see the seals at the spots where the bottom of the springs sat, and in the center. Remember to use molybdenum disulfide based lubricant on the stems and seals upon installation once the work is done on them, it is very important!