Changing rear brake cylinders on 97 malibu. The 2 mounting screws/bolts are tiny torx screws--meaning I need a torx box end wrench to get to it unless I pull the axle. Redicules!

I'm assuming it is the front seats you are removing. There is two systems used to mount front seats, 4 bolt and 2 bolt. Both are easy to deal with. I think the Malibu uses the 2 bolt setup.
Slide the seat all the way forward and look at the rear end of the two runner grooves. There will be a bolt in each runner going down into the floor. It has a star shaped hole in the head. This is a 'Torx' head bolt, either a T40 or T45 size. Remove these bolts. You will probably need to unbolt the seatbelt mount on the floor as well. Tilt the entire seat forward and carefully unclip the electrical wire that is underneath the seat. While it is tilted forward pull the entire seat backwards. It should unhook at the front and lift out.
These seats are very heavy so be careful when lifting them out. Fitting is the opposite to this. Tilt the seat forward and hook in the front ends, connect the wire underneath, lower the rear end and bolt it down.
The four bolt system has two bolts at the front end of the rails instead of the two hooks.

For a 4 cylinder, take negative battery cable off, raise and safely support car, it's from underneath. There may be an underbody cover, 7 screws, then on the starter only two electrical connections, battery cable big nut (plastic cover aside first), and small wire nut, both connections on the starter solenoid. Then the starter mounting bolts, a bolt on top side, and a stud on the lower or bottom side, they kind of angled in, one on top, and the stud on the bottom. When those two loose, starter is free. Oh, yes, on the stud mount is a wire harness retainer, off that and set aside.

Reinstall in reverse. Torque: starter motor bolt and stud bolt-18 ft/lbs. battery cable nut -9 ft/lbs. small wire nut - 44inch/lbs. just snug. don't need a torque wrench on any of them, use your best judgement. 18 ft/lbs is pretty solid tight without agonizing it, 44 inch pounds is like 3 1/2 ft/lbs-use a tiny box end wrench or socket and just tight so the wire is not loose.

The flexible brake hose is attached to a hard line on the body and should be a 14mm open end wrench and a 11mm wrench. The caliper or brake end is usually 14mm and is screwed into the caliper.

All nut and bolt sizes on Audi are metric apart from the torx nuts and bolts.

If its the cylinder for the rear drum brakes and not the caliper bolt it is a e6 female torx socket or wrench that will remove the two retaining bolts.

The only special tool i've needed when doing brakes on a truck like yours is a TORX socket for the rear caliper bolts. Is this what you are trying to do? I'm sure GM makes a special tool just for that, but i've used a regular torx socket with a removable bit. Then used a closed end wrench on the bit and double wrenched it for extra leverage as that bolt is on there tight.

1. Step 1 Mark the brake lines coming into and out of the master cylinder using masking tape and permanent marker.
   
2. Step 2 Orient the tube wrench so that it grabs the end of the nut by first sliding it over the brake line.
   
3. Step 3 Pull the brake lines out of the master cylinder.
   
4. Step 4 Unbolt the two bolts that hold the master cylinder to the brake booster.
   
5. Step 5 Slide the master cylinder off the brake booster.
   
6. Step 6 Remove the bolts that hold the brake booster to the firewall.
   
7. Step 7 Remove the cotter pin from the pin holding the back of the brake pedal to the master cylinder.
   
8. Step 8 Slide the brake booster to brake pedal pin out of the mounting bracket.
   
9. Step 9 Pull the brake booster off the firewall.
   
10. Step 10 Install the new brake booster. Installation is the reverse of removal.
    

You'll need a T-55 torx bit to remove the rear caliper pins/bolts. You can try using an insert style bit...one that removes from the socket or perhaps purchase a replacement bit (one that would be used in a cordless drill/driver.) The one I used had a 5/16" hex shank. Like you said, there is very little clearance between the head and the leaf springs, which won't allow room for a breaker bar and torx bit. So using a 5/16" wrench, ( I'd recommend a 6 point box wrench to prevent slipping or rounding off.) I was able to loosen the bolt. Or plan B is to remove the caliper mounting bracket which is held on by two 21 or 22 mm hex head bolts. Which would have to be removed to remove the brake rotor.

There are 2 bolts on the "inside" on the caliper towards the bottom they use an allen wrench socket.

raise rear of vechicle support it on jack stands.block front wheels.remove wheel -brake drum-then brake shoes.use flare nut wrench to remove brake line from wheel cylinder.then remove wheel cylinder mounting bolts .then remove wheel cylinder.put new wheel cylinder in .do every thing visa versa bleed brakes when done.

Do you mean the shoes inside the brake rotors?