Hi, This is not a hard thing to do. It's just getting the hang of it that can confuse you at first.
You will be using 3 needles now. I would put 28 st's ( your heel stitches) all on one needle, then work back and forth on that needle for the flap. While I am doing that I usually have the instep st's on two needles (14 on each needle) That is more comfy for me, they just hang out on those needles until I have the heel flap all done. After I have the heel flap, I then change and have 14 st's on #1 needle, 28 st's on needle #2(instep), 14 st's on needle #3. The two needles with 14 st's are the heel side. You should start each round between needles #1 .
Also, The place you started your round is always the begining of each round.
I hope you can understand this and it helps you out.