Thanks!
I do it myself. But I got the sample petition and letters from a layer.
1. After I filed, I found that there are a lots mistaken in some recomm. letters. For example, my major is EE, one letter say some words about bioinfo and I forgot to modify it.
2. I am still waiting for my Phd degree evaluation from WES. So I just filed with the notarized copy of my phd degree. It works.
I worried about these issues a lot. Anyway, I got it aprroved without RFE.