If I remember correctly, the tool fits down in the valve guide and is done the same way as if the engine were out. Same deal with OHV setup. He might find that the valve guides need replacing which should be an easy job also.

Good luck.

The Mayans had it right. If you�re going to predict the future, it�s best to aim far beyond your life expectancy, lest you wind up red-faced in a bunker overstocked with Spam and ammo.