Instructions
Play through the game's storyline. Defeat the final boss Red using your best Pokemon to complete the story.
Travel to Silph Co. Headquarters in Saffron City after defeating Red at Mt. Silver.
Talk to Steven Stone next to the receptionist's desk on the first floor of Silph Co. Headquarters. He will ask you to pick from one of three colored stones.
Select the Green Stone to obtain a Treecko. Select the Red Stone to obtain a Torchic. Select the Blue Stone to obtain a Mudkip.