This is not for the US Army's new Army Combat Uniform (ACU) which according to the new US Army uniform regs are not to be rolled up at all.
The US Army developed a way to roll up the sleeved of your BDUs so that the camoflage material still covers the sleeve even after it is rolled up and so that the soldier could quickly pull down his rolled up cuffs in a hurry in case of chemical attack.
From this:

To this:

Step 1: Take off your BDU Blouse (top) and unbutton the cuffs

Step 2: Button the cuff adjustment strap to the nearest button on the cuff

Step 3: Fold over the sleeve inside out until the cuff touches the armpit of the blouse/shirt

Step 4: Pull the sleeve opening apart and get rid of any bunching

Step 5: Fold over the sleeve inside out again, about 3 inches (or 1/3) down

Step 6: Fold the outside part of the sleeve over the top of the folded up sleeve material so it covers all of the inside material, smooth out any bunching

Step 7: Put Blouse/shirt back on and adjust your sleeves so they are comfortable

How to unroll your rolled up sleeves:
Step 1: Grip the lower edge of the rolled up cuff, you only need the outer part

Step 2: Pull down cuff

Step 3: Adjust cuff as needed
Now you look like one STRACK Trooper!
