The package will contain:
The main Borderlands 2 game,
All DLC included in the Season Pass:
Captain Scarlett and Her Pirate's Booty, Mr. Torgue's Campaign of Carnage ,Sir Hammerlock's Big Game Hunt, Tiny Tina's Assault on Dragon Keep, Ultimate Vault Hunter Upgrade Pack 1, Gaige the Mechromancer, Krieg the Psycho, The Heads and Skins included in the Collector's Edition, The Creature Slaughter Dome, The Gearbox Gun Pack, One Golden Key, The Vault Hunter's Relic
1. Launch Steam and log into your account or create a new one (download Steam).
2. Choose "Games" from the menu and "Activate a Product on Steam".
3. Follow the onscreen instructions to complete the activation process.
4. You can find your new game in the "Library" tab.