If the Evee is a boy, put it in the daycare with a girl ponyta. If it is a girl, put it in with a boy ponyta.
You'll need to trade for it or migrate it.
you have to go back to bebe(lady who created the poke boxes) have an open place for it
Go into Etrena Forest from the flowery city above Jublife city then keep walking north the west hen you notice a green stone and level up Eeve there to get leafeon
that would be glaceon and you have to have an eeve and take it to snowpoint city and touch the ice rock then level it up
by transferring it over from another game. Or going on to the gts and trading for one.
Talk to the girl in the house next to Pokemon Center in Hearthome City. In Diamond and Pearl, you can only get it from her after the National Dex In Platinum, you can get it right away
You can go to bebe and talk to her and she will give you an eeve.(Notebebe is in Hearthom city she will give you an eeve only if you have the national pokedex.
I don't know,but it might be the same question as "where to find a eeve in Pokemon diamod
I think eeve is a trade only Pokemon from leafgreen/firered or from Pokemon colusseum.
go to a moss rock level up eeve 1 to 10 times i think then thats leafeon
at the end of the game
get another DS and trade on to platinum