Personally, I'd order the Haynes manual before doing them. The rear
brakes are a little interesting with the internal emergency brake.
Also, you have to back down the screws to release the rear pistons,
don't try to push them in by force.

I haven't done them, although I've read through various notes and
suggestions over the years.

One thing which may be unique on a SAAB (or may be a few other
European cars) is the rear brake caliper and the hand brake
arrangement.  Everytime you pull the handbrake, you're tightening or
advancing the rear pads to squeeze the disc by advancing a screw.

What this means to you when you try to remove the rear brake pads is
they will be stuck unless you back out the screw to loosen the pads.
The SAAB disc brake assembly is pretty well engineered.  The brake pad
retaining bolts and the screw I mentioned are all protected from the
elements by rubber caps.  Remove the cap and you'll find the bolts and
screws are easy to loosen.

I think allen wrench is the only special tool you'll need.