Diff oil change

[Trinity]

Just to make sure that I understand correctly for an 07 H2 SUT - front and rear diff oil change procedure.
1.) Open drain plug on bottom of front/rear diff's and drain all the fluid. Once all the oil is out, tighten drain plug, and then open top fill plug.
2.) Pour 75-90 (Mobil, Purple, etc.) into fill hole until it starts to barely come back out the fill hole. Reinstall fill hole plug and you are done.

At least that is what I did for a Tahoe a couple of years ago and it worked fine. Am I right with this?