Just take a torch and indirectly warm the area of the ring you want to bend. Slight heat and patience with each of the 8 to 10 flaps should give you a nice looking cowl ring.
Just warm it, gently pull it open to a realistic angle and repeat from flap to flap.
It's a great system, just don't melt the plastic so much that you lose too much material to keep it attached to the ring.

good luck.
jw