Rolls and Flutters
Roll 1
The roll is done by contracting the diaphraghm and     
then the lower abdobinal.  Then you push the             
diaphraghm out and then the lower abdominal.  When 
you have enough controll over that, you smooth it out  
to a roll.  It will look like something in your stomach is
rolling down.
Roll 2
The roll is done by contracting the lower abdominal     
and then the diaphraghm.  Then you push the lower    
abdominal out and then the diaphraghm.  When you   
have enough controll over that, you smooth it out to a 
roll.  It will look like somethinng in your stomach is     
rolling up.
Roll with Flutter
When you are proficient in both the belly roll and the   
tummy flutter you may try adding them together.  Try  
panting while doing a roll.
Flutter
The flutter is done by rapidly contracting and releasing
the diaphraghm.  It may help you get the feel for it if    
you pant or try a deep belly laugh.