Instructions
Insert "Pokemon: FireRed" or "Pokemon: LeafGreen" into the Nintendo DS system. Turn on the system. You must earn the National Pokedex. The player must own 60 Pokemon and defeat the Elite Four before the National Pokedex can be earned from Professor Oak in Pallet Town.
Travel to the Sevii Islands in the Kanto region. When you arrive on One Island, Bill will lead you to his friend Celio's Network Machine. Celio needs the items "Sapphire" and "Ruby" to fix his machine. Travel to One Island Cave to find the Ruby. The Sapphire is located inside of Five Island's Rocket Headquarters.
Return to Celio with the Sapphire and Ruby. He will fix his Network Machine. Travel to the Celadon City Department Store to purchase TM28. Purchase multiple copies, if desired.
Attach copies of TM28 to Pokemon in your party as hold items. Enlist a friend's assistance through the use of a second Game Boy Advance system. Insert "Pokemon: Emerald" into the second system. Turn on the system.
Defeat the Elite Four and travel to Littleroot Town in "Emerald." Speak to Professor Birch to get the National Pokedex. Save your game. Turn off both Game Boy Advance systems. Connect the systems using a Game Boy Advance link cable. Turn on both systems.
Travel to a Pokemon Center and speak to the representative of the Cable Club to initiate trade. Both players must have at least two Pokemon in the party to trade. Trade Pokemon that have TM28 attached from "FireRed" or "LeafGreen" to "Emerald." Accept the trade.
Remove TM28 from each of the Pokemon that have it. Both players should trade Pokemon again to restore all of their original Pokemon. Save the game. You will now have TM28 listed in your items in "Emerald." Select it from your items to teach a Pokemon the "dig" ability.