You need a Pokeflute (not a potion) to get rid of Snorlax.
Scroll down to the quick walkthrough if don't like details...
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You may need to have battled the Lavender Town Gym and the Cerulean Gym leaders before you
can get the Pokeflute. I am not sure....
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First you need to travel to Lavender Town before you get past Snorlax.
Lavender Town is where they have the Kanto Radio Tower. Since the power is out, the radio
tower is not working. Fix the power and you'll get the EXPN card (which will give you the
Kanto Radio).
~~~The Pokeflute is a radio station that broadcasts in the Kanto Radio.~~~
So if you are in Vermilion City then you have to go back up to Saffron CIty and travel
East (to the right). Once you are in Lavender Town you have to go to the Power Plant.
It's a little tricky getting to the power plant. Sadly you have to go through the Rock
Tunnel first.
Here are some maps of the Rock Tunnel:
http://bulbapedia.bulbagarden.net/wiki/File:Rock_Tunnel_1_HGSS.png
http://bulbapedia.bulbagarden.net/wiki/File:Rock_Tunnel_2_HGSS.png
http://www.psypokes.com/hgss/gamemaps.php?map=rocktunnel
Once you get out you'll be in Route 10. There is a Pokemon Center right outside. So then
you have to go up to Route 9, go through this little patch of grass, and go down these
small steps to this river. Use surf and follow the river down and you'll end up at the
Power Plant.
The Power plant is purely a one floor room. There are no wild Pokemon or trainers bugging
you to death. So talk to the guy by the Power Plant controls and he will tell you that a
component has been stolen. You have to find it. A Cerulean police officer will ask for
your help.
Go to Cerulean City (careful there are trainers that want to battle you). The city is west
of route 9. You'll find the thief there in front (?) of the Cerulean Gym. He will run
away. You can then find him at the Golden Bridge (north of the gym).
You will battle him and, after you defeat him, he will tell you where the stolen component
is. It is in one of the inner tubes in the Cerulean Gym.
Go back to the Power Plant and return the missing component. Everything will be back to
normal. Go to the Lavender Town Radio Tower and talk to a man inside (i forget which) and
he will give you the EXPN card (the Kanto Radio).
Once you get the Kanto Radio, it will be inside your original Johto Radio. Move the cursor
around to find the Kanto Radio stations (the are not on all of the time).
Fly off to Vermilion City and go to the Snorlax. Open up you Radio (the one in your
PokeGear). Drag the pulsating dot straight up (as if it where north on a compass). You'll
see your Radio say that it is now playing the "Poke Flute" (you'll also hear it).
Talk to the Snorlax and you will automatically be engaged in a battle with it. Defeat it
or capture it and afterwards it will disappear.
And that's it! :D
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Quick Walkthrough =
1 - Get to Lavender Town
2 - Go through the Rock Tunnel
3 - Surf on the River and get to the Power Plant
4 - Talk to person who controls the Power Plant and he will tell you a component has been
stolen
5 - Go to Cerulean City
6 - Go to Cerulean Gym
7 - Talk to Thief who is in front (?) of the Gym (he will run)
8 - Go to the Golden Bridge
9 - Talk to him again and battle him
10 - Once defeated he will tell you where he hid the missing Power Plant component / Go
inside the Cerulean Gym and retrieve the component
11 - Return it to the Power Plant (Go to the Power Plant)
12 - Go back to Lavender Town
13 - Go inside the Radio Tower
14 - Talk to a certain Man and he will give you an EXPN Card (the Kanto Radio)
15 - Fly to Vermilion City
16 - Go to the Snorlax
17 - Open your Radio (it is in your PokeGear)
18 - Drag the pulsating circle straight up and you'll hear the Poke Flute and see it say
"Poke Flute" in your radio
19 - Talk to the Snorlax (by talking to him you will have to battle him, so be prepared)
20 - After you defeat Snorlax, he will be Gone!!!
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Any Questions? Did I miss something?
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