Originally Posted by Shucklulz
Whoever told you that was right up until the part with the guard. You have to stand next to the Snorlax and play the PokeFlute Channel on your Pokegear's radio, then interact with it. Snorlax will wake up and battle you after that.
Oh! Thanks! But how do I get the PokeFlute Channel ? I can't seem to see it on my Pokegear's radio. (I think I didn't get the PokeFlute Channel, yet then !)