If you have ONE horse, go to "breeding" -> "my horses" In the center above your horses name will be a tab that says "my horses" click that tab. You will see a picture of your horse's head pop up. Under his name will be 3 small arrows.
If you have more than one horse go to "breeding" -> "my horses" and click the 3 arrows.
Click them and several options will pop up:
Geneological Tree, a small bush like picture
See This Horse's Offspring, a white foal
RENAME THIS HORSE, a pic of a black and white horse
CHANGE AFFIX, a yellow hand holding a pen
Change this breeding horse, a door.
You can only change the affix on a horse that was born at your stable.

