you go to the game corner and press a while looking towards a poster in the top right corner
In the game corner
After beating the boss at the Rocket Hideout in the Celadon Game Corner.
you get in the team rocket hideout on one of the islands
Floor 1, 2 and 4.
With a special password you find somewhere in the game
You must beat team rocket at Pokemon tower and the rocket hideout then get the 5th badge.
He's first at the team rocket hideout in celadon city, then silph co, then the viridian city gym.
You can use it to operate the elevator in the rocket hideout, under the casino in celadon city. Hope this helped you!
You can get in the rocket hideout Which is in the five isle meadow. You can also get it when participating at the trainers tower. (do single mode battle.)
you have to get the key after beating a team rocket guy then its on like the 4th floor where u have to get through a bunch of spinny thingsnowherei believe it is 'green leaf'
Mt. Moon, Pokemon Tower, Rocket Hideout, Silph Co., Fuchsia City, Victory Road, and Lost Cave.
Go to the casino in celadon city. There will be a rocket grunt in front a poster. Talk to him and he'll battle you. Once you beat him click on the poster and a secret stairway will appear. This leads you to the rocket hideout. At the very end of the hideout is Giovanni. Beat him and he will drop the silph scope