Child please, I used to have a mo-faux hawk and I have got the thickest hair in the world. Here's whatcha do;
I used Garnier gel
It's really thick and top it off, smells really ncie ~.~
So for his hair, seperate the hair down the center, and start working on one side. You're lucky that you're two people working together, I had to get my hawk up myself every morning without any help.
Firstishly just goop on a nice handfull and rub it between your hands and then from root to tip sandwich the hair between your hands and go up, over and over. At the same time, have them hold a blowdryer in their hand and follow your hand up, mainly focusing on the roots because that'll be the foundation - duh. Do that about twice, then spray on the hairspray. Any kind works, but maybe go with Garnier again, and then heat. Repeat for other side.
NOW you want the individual spokes. Just seperate bits of hair from the tip, and then do the same thing you did with the gel, but only on the tips using your fingers. Spray, heat, DONE.