Here's how I did mine...

Cover the side of the fin/dorsal fin leaving about 2" of covering around the leading edges. Place it on an inside corner of a counter. Hold it down firmly and heat the area where the fin meets the dorsal fin, while pulling down at the arrows. It helps to have one person heat while you pull. REALLY stretch the covering over the area, it will go, But you really need to put some heat into it WHILE YOU'RE PULLING. Remember, this stuff stretches as well as shrinks. I used Ultracote simply because it shrinks and stretches better than MK.