For what I have read in my books (Brian & Wilma Rittershausen), you can cut off the stalk of a Phal, cut it in pieces with 2 'eyes' in pieces and place it on some moss in a plastic tray and cover it it with plastic. Keep it moist and a keiki will form and grow. The phal is really easy with this.
I've tried this too and I'm keeping my fingers crossed!