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You give it the EV's it needs (Using Vitamins).
And then level it until it evolves, and when it does evolve you use EV reducing berries. :)
Now it has no EV's, Evolved, and is ready for EV Training.
Pardon me for being human, high and mighty. I didn't realize it was such a crime to make a simple mistake. Allow me to grovel at your feet in hope of retaining some particle of dignity.