Transmission Fluid Exchange

[katie]

I am new to car maintenance, my Aveo is the first of 4 cars I've actually taken care of. That being said, the last time I went to get an oil change I was told I need a transmission fluid flush. From all the research I've done (aka Googled it extensively) I've yet to find the answer to my question-do I really need a flush, or will a simple drain and refill suffice? I've got an automatic transmission and it seems it's having a little trouble switching gears & picking up speed. The fluid is brown so I know it definitely needs new fluid. I am at 67k miles, I bought the car about 7k miles ago and since have changed oil (about to do it again, usually do around 4k), spark plugs, and air filter. Not sure what the best route is for me as far as changing the tranny fluid. I am curious as to the best maintenance schedule on changing tranny fluid as well.