A see my question wasn't clear, sorry.
Here is the story
My friend checked tranny oil level with engine running (mistake #1) and found low level on dipstick.
After that he decided to add some oil and put a non Honda brand (mistake #2).
Now tranny is over filled with non-Honda oil.
If that would be my car I would drain and filled it tree times.
The problem is if that guy will take it to a dealer and tell them this story they will tell him to power flush it. If he refuses it, a single drain and fill will not replace all fluid that is in that tranny.
What is the best way for him to fix this problem?
Would that be fine if he just remove extra amount of oil?