Things You'll Need
Instructions
Remove the protective covering from Slot 2 on the bottom of your Nintendo DS or DS Lite.
Insert the Gameboy Advance game cartridge "Pokemon FireRed" into Slot 2.
Insert your "Pokemon Diamond" Nintendo DS cartridge into Slot 1 at the top of your DS, and start the game.
Go to Route 205 (close to Floaroma Town) or the nearby Valley Windworks.
Place a Level 9 Pokemon at the head of your party, then open your inventory and use a Repel to prevent any Pokemon lower than Level 9 from appearing in random encounters. Because Elekids are Level 9, this increases your chances of encountering one.
Walk around in the tall grass until you get a random encounter. If it is an Elekid, lower its health without killing it (a false swipe is a good move for this), then capture it with a Pokeball.