I feel like a moron for asking this...

...but I would really like to know. I'm fairly new to making icons, I don't follow tutorials really, I just normally play around with things until I get them the way I want them. But I've seen some icons around lately that I liked and someone suggested I try to find a tutorial for how to make them/the effects in the icon. So here I am trying to follow it and everyone I see says something about "desaturate the first/second/third layer"; how do I desaturate layers? I'm using PSP 9 (which is almost exactly the same as 8) and I tried using the Help tool for it and that gave me nothing.

So could anyone please tell me how do you desaturate layers?

Thank you in advance.

Thank you all for your great suggestions! Problem solved ^_^