Transmission fluid change questions

[smdimjesus]

e53 x5, 156k miles, going to change the transmission fluid.

I plan on draining it and then just filling it, nothing to crazy, my questions are how would I select the correct fluid, and are there any additional steps. I've checked out this guide https://www.xoutpost.com/bmw-sav-for...hange-diy.html and It mentions that I'd have to run through every gear. I have an automatic, but it does have the feature that allows for manual shifting. Would I do that?

Are there any other precautions or thing that I should consider before doing this, I've seen how opinionated people are about this subject and just want to have a good idea about what to expect.

Also thinking of doing TC fluid at the same time