It really isn't that hard just make sure you install it in the correct direction. Best thing is to observe the seal direction before you remove it. Avoid touching the surfaces of the seal and you shouldn't need to clean the seal surface unless you touch by accident. And if you do, then just use a little alcohol with a clean cloth.

Here is a video of someone replacing a seal on a Tristar which is the same as the EcoStar.

http://www.youtube.com/watch?v=C_x6h1D33rM