It's not hard at all. I was very worried to attempt it on my own because I didn't have VAG-COM to monitor the temps, but I didn't do it that way.
Buy the parts yourself (you can find kits online with the oil, filter, gaskets etc). You have to take out your intake, battery and battery tray to get to the DSG filter, but it's super easy to do.
Let your car cool off (i left mine over night). I started it, drove it up on ramps and shut it off immediately. Cracked the bolt and let it all drain out. I measured the amount of fluid that came out and filled it (from the top) with the exact amount of fluid drained, plus a splash more to account for what was soaked into the filter. (IIRC, it was like 4.5 quarts)
I spoke to a few people who have done it that way and haven't had any issues. If you're replacing exactly what you took out, you should be fine. There really isn't a need to monitor the temp in my opinion.
What takes the longest is filling back up the tranny. It takes a while to fill it back up with fluid. It's worth it though when you look at the amount of money you'll save over the dealer hah
