Didn't mean to sound so curt, its just that there is so much that is covered in the manuals and the help files. I ran a search for curves in the help files out of curiosity and detach curves was the 2nd item on the list. Then I checked the NURBS modeling reference index and found that chapter 4, page 111, covers "split a curve or surfaces (detach)."
I agree that questions are absolutely required for learning, but I am also a firm believer in checking available resources first. Maya's help file has tons of written tutorials on how to create and edit various model types. This what I mean by brushing up the basics.
Water under the bridge now as they say. Where did you get the tutorial for the head? It looks familiar, like one where a couple people have gotten stumped on lofting from the upper eye lid.
Good and luck and enjoy learning Maya.
"If you love your job, you'll never work another day in your life."