Play your radio, then talk to it. For me I just had to play the Pokemon music station but there is also this Pokemon lullaby at the very top of the radio selection list that people say that is what you're suppost to do(it wasn't for me though). I could be wrong -->(i forget) but in order to get the Pokemon lullaby one, i think you have to save the radio station from team rocket then go to a radio station somewhere(in Kanto somewhere). they should give it to you for thanks. i could be wrong and if I am, please, someone improve my answer.
The Pokeflute!!!!
You get the 2nd radio card and click on the top talk to Snorlax and he will wake up.
you need to have a poke flute. by unknown
Go to the Snorlax. Go to your poke'GEAR. Go to the radio setting. On the top of it is the poke'flute. Play it. Then exit. Then he will wake up.
You wake up Snorlax and go through Diglett's Cave.
you get more radio stations from the radio station then go close to snorlax and turn on the radio station at the top called pokeflute and he will wake up
You go to your pokegear and bring the star to the top, so that it will play the pokeflute. Then while its playing click on the snorlax, then it will wake up. The snorlax is lv50 when you fight it.
use the stylust and go to the top star on the radio.
You must use the pokeflute on the radio to wake up the Snorlax blocking the path. The Snorlax will attack you, and there is a 55% chance that it will have leftovers.
Snorlax wakes up anyday, if you play the poke flute on the radio nearby it. Put the poke flute tune on, and encounter Snorlax
there is no Pokemon flute. the way to wake snorlax is to get the adapter for your radio in lavender town
go to the top of the lavender city graveyard and you will recieve it