That spring can be preyed out with a couple of screw drivers.Unbolt the motor from the pump casing and tap the edges of the pump end. It should pop off. I would replace the shaft seat along with a a new casing gasket and guide vain O ring. The area where the shaft seal sits in should be cleaned thoroughly and the porcelain and rubber should be lubricated with K Y jelly. The seal can be pressed in using a socket as well as the spring. When pressing in the porcelain ring be careful that you press it in evenly so the rubber wont tear.