Question: how to evolve my eevee into glaceon?
Answer: Head to your nearest Poke Stop and apply either the Mossy Lure for Leafeon or the Glacial Lure for Glaceon, then find the Eevee you want to evolve in your list. If done correctly, the "evolve" button should display the silhouette of either Leafeon or Glaceon, so you can be sure it's working correctly.