Hearthpwn

The main combo we want to use is Warsong Commander / Grim Patron, so you should mulligan for those cards.  

On turn 2 or 3 you should try to kill some of his minions, because you don't want to take to much damage to the face. Therefore use Explosive Sheep, Cleave or Doomsayer. If you don't have those cards and still miss the Warsong Commander or Grim Patron try to draw cards with Battle Rage, Shield Block or Acolyte of Pain. If you have the Warsong Commander, you can play it already on turn 3 or 4. Since he prefers to go to the face the Warsong Commander is safe. 
Hopefully you can play Grim Patron on turn 5. The board should be full with 2/2 minions, so most likely you can clear his board and your board is full with Grim Patrons. If you can play a Frothing Berserker on turn 4 it is even better, since he gets buffed insanely. Always consider on the first turns which minion(s) he can summon the next turn with his hero power.
After you played the combo he plays most likely Revenge to kill your Grim Patrons. Even better if you could play a Frothing Berserker before. Try to go for the next Grim Patron, which you can duplicate with Whirlwind, Inner Rage and so on.
If you don't have the combo just try to survive as long as possible. Clear the board with Brawl, kill Gyth with the Big Game Hunter or Execute. A double Whirlwind (or with the Deathrattle from Death's Bite), can clear the 2/2 minions and buff the Frothing Berserker, which can win you the game if you have Warsong Commander on the board.  When his board is full you can also easily play the Sea Giant.
In the case you can't remove his minions and you don't get the combo soon enough you die :P

I hope you enjoy playing the deck.

The video shows an example how it can work out