Mona:
Don't know where you are, but in America (and, I'm sure, the UK, Ireland and Germany) the auto parts stores sell a "spout" for a transmission oil bottle that screws onto the top of the bottle, and has a long (18 inch?) clear vinyl tube with a plastic tip on it. It also has a valve in the top that screws onto the bottle to allow you to turn it on and off. You simply screw it onto the top of the bottle (in the "off" position), place the tube tip into the filler hole, turn it "on" and squeeze the bottle repeatedly to fill the tranny. It usually takes a couple of bottles (each is a quart?) to fill it properly.
To change the oil in the tranny, get the entire car up on jack stands so it's about 1 foot up in the air, and remove the left rear wheel. Look at the bottom of the tranny case, and you'll see a hex-shaped plug in the bottom of the bulbous part of the transmission case (it looks like a giant hex screw). Place a pan under the tranny, and, using a suitable sized hex wrench (available at Sears tool department), remove that plug to let the oil drain out.
Once it stops draining, coat the plug threads with thread sealant (Permatex thread sealer, from an auto parts store) and replace it.
Now, look on the driver's side of the tranny case for another hex plug just like the one on the bottom. That's the filler hole. It screws in horizontally from the drivers side. Remove that plug, insert the tip of the oil filler tube in the hole, turn on the flow and squeeze the bottle repeatedly until it empties. Load up another bottle, and repeat, but slower this time, until the oil begins to run out of the hole (it probably won't take much from the second bottle). I usually place a catch pan under it and let it drain for a few minutes, then squirt another couple of squirts into the hole to make sure it's full, and then, having already applied thread sealant to the plug threads, replace the plug in the hole and tighten nicely hand tight with that big hex wrench.
OBTW: DON'T TIGHTEN THOSE PLUGS TOO MUCH!! Just nicely hand tight with the long end of the hex wrench is fine, as the sealant will stop any leaks. Too tight and you run the risk of cracking the aluminum tranny case. tighten til you get good resistance, then another 1/4 turn is fine.
Lastly, if you're changing tranny oil after the first 600 miles or so, you can replace it with 90 wt. Synthetic oil and you'll probably find that it shifts easier (I did).
This whole process can be done in your home garage in less than an hour, if you have four jack stands (or a lift at a friendly garage) to get the car up onto. It should be level when you're draining/filling the transmission oil, since you're filling the case to a level point with the side filler hole and you want it to be right.
Good luck, and don't be afraid to ask more questions..
Gordon
One of the "Speedstah Guys" from South Carolina