You have to use your pokeflute that is in the radio section of your pokegear. If you don't have that, go to the radio tower in lavender city and talk to the man and he will give you an upgrade for your pokegear.
You have to move snorlax and go through diglet tunnel to the east of vermillion. It will take you just south of Pewter City, where gym 14/Brock is.
When you beat snorlax
Play Pokemon flute song
you go to blackthorn city and you find a house near the pokemart
you dont make poffins in soul sliver
go to your radio move the target all the way to the top to the poke flute it will wake up
There Isn't
you have too get the pokeflute on the radio after you finish thr power plant problem
Complete the Power Plant sidequest and go to Lavender Town. The man in the Radio Tower will load it on your PokeGear. Then, just play it and talk to Snorlax.
in the radio tower
You have to go to the Lavender Town radio station. Talk to a man in a suit near a sign on the wall to get the radio attachment for Kanto. Then, use your stylus to put the cursor on the radio to the top middle to find the PokeFlute channel to wake up snorlax.
beat all 16 badges and talk to profeser oak