Have a pen and a paper ready.
1. Talk to the son, who will show you the paper that his father gave him.
2. On the top, you can see a bunch of runes, on the bottom, you can see a bunch of numbers. The runes are the numbers are connected with the lines. Follow each rune to its number and write them down.
For me, the lines were as follows (scroll down for spoiler):
Code:
Hammer -> 3
Pick -> 2
Boot -> 1
Beer -> 5
Shovel -> 4
3. Next, write down the runes in the order of the number shown on the drawing.
4. Zoom in and shuffle around the runes to the order you wrote down in step 3. To shuffle, you need to click on the two runes that you wish to shuffle.
For me, the right order was (scroll down for spoiler):
Code:
Boot, Pick, Hammer, Shovel, Beer
5. When you get it right, a dialog will pop up and a wall open right behind the machine.