You have to fix the power plant and then go to Lavender town radio tower.
You will receive it from a person in the Lavender Town Radio Tower.
You must obtain a radio card from the receptionist at the radio tower
when you get to goldenrod city you go into the building where the team rocket grunt is standing in front of the you talk to everybody in the building and some person will give you the radio card
The EXPN card is on the first floor of the radio tower in Goldenrod city.
use the stylust and go to the top star on the radio.
you only get the card in heartgold and/or soulsilver
You need to get the radio card.
The expn card automatically attaches to your radio now you can tune into kanto radio!
You talk to Whitney{Pink-haired girl} and she'll quiz you. If you answer all the questions correctly, she will give you the Radio Card.
You have to listen to Buenas password in your radio on the pokegear. Then you go to the radio thower and talk to Buena and click on the anserw you heard on the radio.
The card key in Pokemon Heartgold and Soulsilver is located in the Goldenrod Underground.
there are only 2 radio cards!
You will receive it from a person in the Lavender Town Radio Tower.
you get a map card for your pokegear in the second town you visit in the game an old man gives it to you
Go to lavender town and go in the radio station. Then there is a man facing the wall so talk to him and he will give you the EXPN card.
First, you need to have the Kanto radio card extension from the guy in the Kanto Radio tower in Lavender City. Second, you need to open up the Pokegear to the radio while in Kanto. Finally, just tap your stylus to the very top tiny star on the radio to go to the PokeFlute station.
go to diglett cave by vermillion city and play the pokeflute to wake up the snorlax