A trouble maker is someone who causes trouble.

Blocked the way of the van implies the troublemakers stopped the van from continuing on its journey. They may have used another van or some other tactic.

Pulled off means to succeed in carrying out something.

A heist is a robbery.

So, a bunch of robbers, who are causing trouble,  committed a crime by stopping, maybe a van full of money or gold and successfully stealing the items.

Lol!

If there anything you haven't understood, do let me know.  I enclose news of a heist  near Lyon, France where the robbers stole £1.3 million worth of powdered gold.

http://www.bbc.co.uk/news/world-europe-38292968