PO400.....EGR Valves......Where is it? How can I clean them?

I have 99 Maxima. It only has 39,000 miles on it but got the 'service engine soon' light today. When I took it to Autozone, they told me that EGR Valve needs to be cleaned out. (P0400)

I am trying to do this on my own. They told me that it's very easy.
Can somebody please tell me where I can find this darn thing?
It will be great if you can attach a pic or link.

Also, I can I clean it out? What is the procedure?

Thanks!

It is my understanding that 99 and newer versions have totally different looking EGR. I still have no luck locating it.......
Please help....

Common guys.....