Things You'll Need
Instructions
Insert your copy of "Pokemon: Fire Red" into your GameBoy Advance. Insert the copy of the other Pokemon game into the second GameBoy Advance and connect the two systems with the transfer link cable.
Turn on both systems. Travel to any Pokemon Center in "Pokemon: Fire Red" and place Eevee in your party. Talk to the trade attendant and save your game. Travel to any Pokemon Center in the other game and talk to the trade attendant. Save your game. Select "Trade" on both systems to begin the trade process.
Select Eevee from "Pokemon: Fire Red" and any Pokemon on the other game. Select "Confirm" to initiate trading. Once Eevee is on the other game, leave the trading room.
Increase Eevee's happiness by giving it vitamins, using it in battle, attaching the Soothe Bell item to Eevee and taking it to the masseuse. Once its happiness has been increased to the limit, raise Eevee's level by one between midnight and noon to evolve it into Umbreon. Return to the Pokemon Center.
Talk to the trade attendant and trade Umbreon to your copy of "Pokemon: Fire Red." You will now have Umbreon in your game file.