I have a Hamilto bay ceiling fan with remote, I need the fan to go the other way around so the air will go down instead of up to the ceiling, There is a way to do it with the remote but I forgot. The remote has six bottons, two green ones that turns on/off up and down light. Three gray for the fan (low midium hi) and another one bigger to turn it off

Ceilingfanrepair will catch your post later and he will know more than most of us. There is a small black slid switch in the side of the motor housing that reverses the fan direction. I am not familiar with a remote operation that will do this.

I never caught the question because it is in HVAC, not electrical where I live.

I am only familiar with two ways to reverse a remote fan: either a slide switch somewhere on the fan body, as Ballenger says, or a button on the remote that says "reverse".