remodeling crew necklines?

[le-soleil-noir.livejournal.com]

Does anyone have tutorials for re-doing a t-shirt neck line?
I have a bunch of crew neck band shirts and i want to turn them into boat neck or v-neck. I DO NOT want to just leave a raw edge, though.

EXAMPLE

I'm looking to do something like this:

(that pic is from http://mateywear.blogspot.com/)

I can kind of figure out what is going on, but I'm still new at sewing, so tutorials would be BEST.

Thank you very much :0)