I assume you just want to do a "drain and fill" procedure.
There really isn't a detailed How To/FAQ on this forum, but it's not too hard. When I first got my car, I googled: Infiniti M35/45 transmission fluid change and I found another enthusiast site that has detailed photos for this DIY.
1. Basically jack up/place car on jack stands so it is level.
2. Find transmission pan drain plug (it's in the corner of the pan.)
3. Drain plug bolt I believe is 19 mm bolt head - line up drain pan with plug
4. Loosen plug and let fluid drain
5. You'll want to measure how much fluid you've drained out, because you are replacing that exact amount with new transmission fluid. (most folks advise to use Nissan Matic J or equivalent fluid so you don't mess anything up.)
Total transmission fluid capacity according to owner's manual is 10 7/8 quarts, so drain and fill should be less, since you aren't completely dropping the pan, etc.
6. Clean off drain plug and replace, torque to 25 ft-lb.
7. Transmission fluid fill/dipstick is 10 mm bolt.
8. Refill amount drained with new transmission fluid, replace transmission fluid dipstick and torque bolt to 45 in-lb (note inch-lbs)
9. Drop the car off ramps/jack stands/jack and start engine, run through gear selector, go for short 5 minute drive.
10. Check transmission fluid dipstick and see if level is within specs.
If you decide to do this, take some pics and you can make the How-TO/DIY.