This is very simple and legal!

Requirements

* Steam Account
* Paypal ( Or another method of payment though steam)
* Patience

1. Go to Save 10% on Counter-Strike: Global Offensive on Steam and go to "Pre Purchase Counter Strike Global Offensive" And hit add to cart
2. Purchase the game
3. Wait till August 14 and you will be invited to the beta by valve.
4. Have Fun!

Now this might be a bit pointless but i wanted to make this to anyone that's trying to get into the beta. Plus its 10% off till the game comes out which is added bonus!