3.6L 6 speed trans flush advice please

09 malibu 3.6L 6 speed with 50,000 miles on it. I was reading the owners maual and from what I understand the fluid is "lifetime" unless you fall under the severe duty catagory and then you need to change it at 50,000, is this correct?

I don't think I fall into the severe duty but I think I would like to change the fluid as a preventative maintenance thing, don't think it can hurt can it?

So if I do this do I need to flush it or can I drop the pan and drain and add new fluid? Also is there a servicable filter I need to change?

Any advice with this would be much appreciated,
Thanks,
Scott