You simply talk to the Rocket Grunt next to the poster at the back of the Celadon Game Corner and he will fight you. If you win, he will leave. Talk to the poster, and some stairs appear. Go down them.
In the game corner
You must beat team rocket at Pokemon tower and the rocket hideout then get the 5th badge.
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
With a special password you find somewhere in the game
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!
Mt. Moon, Pokemon Tower, Rocket Hideout, Silph Co., Fuchsia City, Victory Road, and Lost Cave.
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'
If you are talking about the Pokemon Tower, then first, you need the Silph Scope, which you can obtain by beating Giovanni in the Rocket Hideout at Celadon City, in the Game Corner.
go catch a POKEMON bring it on