If you look closely the screws should have little score marks on them somewhere near the head that tells you in which order they go I, II, III, IIII from left to right.
Just find the holes, make sure the screws go throught the right bit of the dash and screw them in (they go in from bottom to top). They have a torx head so you'll need the correct bit (or the driver in the Saab toolkit).
I'm pretty sure that at least one of the holes requires the removing of the ashtray, the other two are either side of the steering wheel.
These are the long ones that come up from the bottom of the dash, right?
They should be marked with hashes near the head of the screw. These hashes indicate the position they're installed, left to right. Leftmost is the screw with one mark and rightmost should have four marks.
They do take some fiddling and wiggling to get in the correct position. If the sleeves that the screws travel through are missing or misaligned, this can make things a little tougher. You can wiggle the fascia slightly to get things lined up.
I found doing the middle two first made it easier to get the outsides. In taking three different fascias off, I've found all three had one or more broken guides at the top of the fascia. Having these missing or broken will mean some squeaks and rattles. There's a recent post about rehabbing these, I think.