Here is the step-by-step picture instruction on how to program/add additional keys with gm tech2 scan tool.
Vehicle model: Saab 9-3 Sport 2004
GM Tech2 diagnostic scanner (cheapest $289 in obdii365)
Saab TIS2000 software CD
Adding keys with tech2 gm tool:
Install TIS2000 software
Connect tech 2 scanner main device with vehicle via OBD socket