all you have to do is get the kanto radio and put the little dot in the middle top and the Pokemon near diglett's cave will wake up and you will need to battle it and then you get threw the cave
Pewter City
You can fly there or go west.
At the top of pewter city in the kanto region
talk to the man on the platform in pewter city
Its in Kanto to the right of Pewter city.
go down at pewter city
to pewter city
go to the museum in pewter city
After you get the silver wing from the old man in pewter city
Go north from Viridian City or south from Pewter City.
In kanto, south of pewter city, north of viridian city.
In Pewter City. There is an old man on a hill that gives you a silverwing