we did that at our old house, its pretty simple, you can buy the gas logs at Home Depot (or similar) and put them in pretty quick like. The newer vent less ones are pretty sweet, that's what I had back in Atlanta and we could keep the flume closed and it heated the house up very nice like..
I think you disconnect the gas starter and hook the gas log (feed line) into that, just take some soapy water and rub on after you install it and if it doensnt bubble up then there are no leaks.. even a caveman can do it