Read through this for a guide on how to increase affection in Pokemon Amie.
As for Friendship, since the hidden data is currently inaccessible for the time being there are know exact values of what it does to your Pokemon's friendship. However, there are things that do increase happiness, such as:
- Walking 128 steps
- Massaging your Pokemon in Cyllage City
- Make your Pokemon use vitamins
- Level up your Pokemon!
- Use the Soothing Bag in Super Training
- Using either the Pomeg, Kelpsy, Qualot, Hondew, Grepa or the Tamato Berry. (EV lowering berries)
- Pokemon Amie (still a rumour)
However, since you don't want an Espeon, you can trade your Eevee to reset it to it's base friendship, or you can make it faint multiple times. Tough love, right? :3
Hope I helped. :)
Source and Above Link