There are two more headings than you need.
Parts of the text:
lines 1–9
lines 10–14
lines 15–21
lines 22–36
lines 37–48
lines 49–53
Headings:
a) Money made from Banksy's art
b) Cooperation with Blek le Rat
c) Unlawful art getting global fame
d) No idea of what to do with illegal artwork
e) The hidden star
f) How people celebrate Banksy's fame
g) Discovering a new technique
h) Famous graffiti with a political message