Step 3: sabotage some headphones.
you need two miniplug cords for this- i used ipod headphone cords because they look really nice.. but they were a pain to use and solder to, becasue they are insulated with some kind of lacquer. you need to use sandpaper to remove it or annihilate it with the soldering iron and tin it.
Then solder the cords to the places that you found inputs and outputs. (or the wires to the speaker and mic if you had an intercom)
you may want to try this with crocodile clips first.. becasue i found that i could only attach 3 wires.. if i grounded it twice with the 4th.. my sound card got angry.. again- guess and check, sorry!