1. Figure out what suite goes with which card number on the left side then press the card in the middle to see if it's correct. If it's correct, it'll change to another card.
The suite on the right is always the same one as the current card in the middle.
Press the buttons in this order:
Heart + 8 + 5 heart card
Club + 10 + 8 club card
Heart + J + 10 heart card
Diamond + A + king diamond card
Spade + K + queen spade card
2. Now you have to figure out the code.
The code numbers are equal to the number on the left side +/- the value of the suite on the right.
Since the first pair of buttons was 8 and the heart suite, 8-2=6.
10 and club = 10+1 = 11
Jack and heart = 11-2 = 9
Ace and diamond = 14+3 = 17 (Ace in this case is equal to 14)
King and spade = 13+5 = 18
Press the keypad and enter the code: 61191718