Hi @hexdump ,
Here are two alternatives to Omar’s method.
!. (What I would probably do in this specific case, is:) Delete the new Faces and recreate them, this time how Jonathan Lampel did it.
2. Apply the Mirror Modifier of those new Faces, Inset, Delete ‘half’ and Add a Mirror Modifier again.
All three methods are worth knowing and remembering; they will come in handy and depending on the exact situation one might be slightly better than the other (but mostly it’ll be just personal preference).
