Roll out the awning completely.
Drill a 3/8-inch hole at a 45-degree angle in the straps' groove. Drill the hole a couple inches from the end of the the roller tube.
Insert the new strap into the hole and slide it to the middle of the tube.
Cut off the old strap using the utility knife or scissors. Flush it with the roller tube and leave the part inside the tube there.
Turn the loops inside out to keep the loops open. At the fold put a bead of silicone to hold the loops in place. When dry, turn the strap the correct way.