Here is what I just did and that was before I read your reply.
I went under the truck. Since it says in step 2 that the engine must be running at idle I started the truck. I went under the truck to unscrew that fill screw and no fluid came out. I got a wire from coat hanger and wanted to put it in there to see the color that fluid would leave on it. I wasn't sure if there are any moving parts in it so I didn't want the transmission to catch on this metal wire so I decided to stop the the engine. Once I did that and was going to get back under it - I noticed that the fluid started pouring out of the overfill screw. At first I thought it was just some extra fluid but it wasn't anywhere close to stopping so I realized that as it was circulating through the transmission and then I suddenly stopped the engine it probably kept moving my enertia. Pretty soon I had a huge puddle of it on my garage floor. I have just finished whiping it off and since half of it was already lost I decided to unscrew the drain screw and drain it all.
The gaskets that I found on the screws it were not made of copper and look more like regular metal or nickel gaskets and I can see a little of silicone there between the screw and the gasket - I guess they were not too tight on the screw. Should I replace them with copper instead?
Also I don't have a torque wrench, if I just use a regular drive with a 19 socket should I be afraid of overtightening it or ruining the thread by tightining it too much?
Would I use the Syringe-Pump you mentioned to put new fluid back in? What do people use to pump it in?
Also do I use regular Dextron III or is there such a thing as Fully Synthetic Dextron III or anything else that would be better to put in?