2015 Q50 Transmission

So my gasket is out between my pan and transmission and it leaking a tiny bit but I’m bringing it to Infiniti tomorrow to get a new gasket and drain and fill ( I have 135K and my trans has never been serviced apparently) I’m wondering what’s y’all’s opinion or experience with doing a drain and fill on y’all’s trans? I’ve been told don’t flush these so I’ve emphasized to not flush it