Spark Plug Seals

Is it me or are those seals a pain in the butt to replace. Does anyone have a good way of replacing them.

Are you talking about removing old or installing new? You are talking about the sparkplug tube seals that fit into the valve cover heads?

I used a bolt with big washers and a nut to pull the new seal into place. One washer on the outside of the valve cover and one washer on the seal. Worked like a charm. No need to drive it with a hammer at all. Most important thing is not to push it in too far or you will not have enough overlap with the sparkplug tube to create a good seal.

What engine?