What is the procedure to replace valve stem seals with the heads on?

Which valve stem seals should be used; O rings or umbrella style?

 

You will need an air compressor and the appropriate fittings to adapt to the spark plug hole. With that, you can start by removing the valve covers. Then the rocker arms. After that, you can use a valve spring compressor to push down on the spring, allowing you to remove the keepers. Finally, you can remove the old valve seals. Work one at a time.

You should buy a manual which should cover the torque specs as well as the requirements for tightening down the rocker arms once you are putting everything back together and running the final tightening sequence.

 

I do not have an air compressor.

My main concern is what type valve stem seal does this forum suggest ?