Changing transmission oil in a K46 transmission

I have a 2006 JD X300 with a K46 transmission. I am not mechanically inclined, but can do simple things. That said, is there any way to change the transmission oil on the K46 without removing the transaxle and the transmission? I see a cap on the left hand side of the transmission that I can access without removal of the transmission. Does removal of any of the bolts located under the transmission allow the transmission oil to drain? Any help or info would be appreciated. I have over 800 hours on the lawn tractor and I have notice noises in the transmission and a slowing down of the tractor movement.