I've tried to attach a picture of the fill plug. Basically there is a plug that looks like a nut that gets unscrewed and you add the Honda ATF there.
You may need to look at a service manual to find it's location.
If you're not sure about any of this you should go to the dealership and have them show you. It's important that you don't overfill the transmission.
〉 Answered on Apr 11th, 2007 by Lori Johnson, Owner and Instructor at Ladies Start Your Engines