The one I used was
Lost Saab Keys and if you do have to do this...look on the bright side...they now have instructional videos on how to do this!
They dont say anything in the video about being careful not to discharge the air bag...I dont know if that is a risk, I did some reseach when I did it, forget most of it but I disconected the battery and took out the fuse...prob some other stuff, so I recomend you research it.
BTY....replacing the battery on your FOB takes 39 seconds... 5 seconds to open the key and take out the battery then 34 seconds to ask the guy at home depot/ Lowes where that battery is.