Most auto parts stores sell a valve spring compressor/clamp that will compress the valve springs enough to remove the keepers with no problems. I did mine on my 1980 using an old spark plug that i removed the end off of and welded a male air line coupler to it, and screw it into the spark plug hole. Then hook up your air hose to it with 10-20 P.S.I., it will force the piston all the way down to the bottom. The key is to leave the air pressure to the cylinder until you have replaced both seals, and have the keepers all back in place, then move to the next cyl., etc. I call it McGyverizing, but it has worked well for me in the past on most all overhead valve engines. Hope this helps. Regards.
