HELP! Please Walk Me Through the Heel Flap

I've finally been able to set aside some time to knit now that the baby is napping but mama brain is in full effect and I don't understand the heel flap instructions on the Monkey pattern. If anyone out there has the time, could you walk me through it? I could just muddle through the pattern but I'm trying to finish these up this weekend and I don't want to mess up and have to unravel and restart. Thanks in advance my Monkey friends.