How to start modding and unlock decks

The below information taken from somethingawful forums

Necessary steps to start modding the game

Extract Data_Core.wad and Data_DLC_0004.wad by dragging them onto Gibbed.Duels.Unpack.exe
Data_DLC_0001-3 only contain backgrounds, avatars and such so you don't need to worry about those unless you want to mess with the interface graphics.
You now have Data_Core_unpacked and Data_DLC_0004_unpacked, each containing a folder of the same name but without the _unpacked part. Move the folders named Data_Core and Data_DLC_0004 into the main Magic folder. There's 50000 files in Data_Core.wad so it may take a while.
To get Magic to read the files you just extracted instead of the original wads, you need to rename originals. I add a _ at the beginning, renaming Data_Core.wad to _Data_Core.wad and Data_DLC_0004.wad to _Data_DLC_0004.wad You can also just move them elsewhere. Be aware that if the game patches it will recreate these files.
Do not make a new .wad with the Packer afterwards, that's mainly for if you want to distribute a pack of new cards decks or something like that. If there is a .wad file the game will not load the directory of the same name.

Open data_core\data_all_platforms\data_required\frontend\common\ui_scripts\core.lua in Notepad
Search for "SECRETBUTTON". Change the first occurrence to:

   SECRETBUTTON:setVisible(1);

Download http://dl.dropbox.com/u/7636448/deckmanager.xml and put it in data_core\data_all_platforms\data_required\frontend.
Unlock Deck can be used to unlock decks you don't have yet or to unlock all cards in a deck you have. You need to leave the edit/preview deck screen before the change take effect