First you must register or log in. You can do this either with your existing VfB Shop account, your Google account or with your e-mail address. The player cards are primarily available by purchasing packs. These are available as single packs (€9.99), packs of three (€19.99) or packs of five (€29.99) and each contain a random selection of players.
The cards can also be purchased by swapping them with other users.