I ran into this same problem. What I did was:
1) Take the head into edit mode
2) Select vertices in the shape of the hair you want (like Kent did with the mask tool, in his method.) The lasso tool makes this easy.
3) Duplicate your selection (shift+d), and then separate by selection(p->selection)–now you have a new mesh exactly the shape of your selection.
4) Go into edit mode with your new mesh. Extrude, and don’t move it (e, esc).
5) Scale along normals (alt+s) and you will have the same shape base mesh that Kent did.
I also applied a decimate modifier to this base mesh, since it was rather dense. At this point you can follow along again.
