I did mine myself. They make a special hooked tool for this purpose. Other wise use any means you can come up with to pry it out but not harm the aluminum housing. The seal will be completely mutilated in order to remove it. Use white lithium grease or similar to install the new one. Be aware there is no seat. If you keep tapping it will keep going in. Tap it in with a socket or similar device just until it is flush with the front of the housing.