What services should be performed, and what is the usual and customary labor & parts for just the routine 90K service?

I have gotten conflicting opinions on changing the transmission fluid. A knowledgable MB tech says he does it on his own cars, even though it's not recommended by MB.

He cites 3 issues 1) use the right fluid 2) have a special tool for opening both torque converter & pan 3) have a MB fluid level measuring device (there is no dip stick)

Any comments on these recommendations?what is the usual and customary pabor & parts for just the routine 90K service