Toyota Repair: valve stem seals, toyota cressida, 5mge

Question
What is the easiest way to replace the valve stem seals on a toyota 5MGE engine? This engine is a 6cylinder with twin overhead cam made for 1985-1988 toyota cressida.Thanks.

Answer
Although this can be done without removing the cylinder heads requiring some special tools I think the easiest way is to remove the cylinder heads and then send them to a machine shop to have the heads overhauled by grinding the valves which includes replacing the seals.That's the easiest way, the hardest way is to try to do it in the car without removing the heads.