How do I change transmission fluid on a sealed transmission?

I need to change my transmission fluid on a CVT transmission that is sealed. I have looked up some videos, but I trust you since you helped me along the way with my right side of my truck that needed the CV joint, lower control arm, and the strut package replaced and you were there with me the entire time answering any questions I had and offering advice and videos. I just need a little help with the controlled variable transmission because it is sealed, and I haven't ever had one of these before and I'm a little confused with the instructions that the guy at the parts store gave me.