How do I win tickets to the Harry Potter and the deathly hallows part 2 premiere?

I want to win tickets to the london one. They are in both trafalgar square and leister square.
I know you can win them an facebook, but I want to know different ways to.
Thank you!

What is a VPN?

VPN is (Virtual Private Network) were first used by companies to enable their employees to securely access internal systems such as email remotely (e.g. from home or while on business trips). Today they are increasingly being used for personal use by individuals to protect their privacy while online in public places (e.g. when using the wi-fi connection in a cafe) or in a country where the internet is censored / blocked (e.g. China, Saudi Arabia…).