To do this you need a Pokémon that can DIG. First you enter, then go to the 5th floor and go left until you see some bushes/trees. Go down but don't go on that portal simply go down the narrow path and beat the Team Rocket guy.
Then go to the portal after you were transported, and go back in that portal. Go down one step then go right and pick up the CARD KEY (which is the POKÉ BALL). Then if your Pokémon needs healing, DIG out and heal at the Pokémon center. Then go back in the building and go to the 3rd floor. Defeat the guy from Team Rocket.
Go to the left open door with the CARD KEY and go in the portal and you will see Gary your rival. Beat him, then talk to the guy and he will give you a LAPRAS. Then go into the other portal and go down and beat the guy from team rocket and go fight Giovanni. But only fight Giovanni if your Pokémon are in good health!!! then talk to the guy in the room and he will give you a prize!!
I hope this helps. Bye

yes it dose i did it in 1 minute ty