Instructions
Start a new game in "Pokemon Ruby." Defeat Roxanne, Brawly and Wattson, the first three gym leaders, to obtain the first three Sinnoh badges. You will meet Team Magma before you defeat the fourth Sinnoh gym leader.
Go to Verdanturf Town, go to Wanda's House to talk to Wally. Go to Rusturf Tunnel. Use Rock Smash to break the rocks. A man will give you "Strength" (HM04) to thank you. You can use Rusturf Tunnel to travel to Rustboro City.
Travel from Verdanturf Town to Mauville City. Walk north to Route 111. When you come across rocks blocking your way, use Rock Smash. At the end of Route 111, you will see a desert, which you cannot travel through without Go-Goggles.
Walk west until you're on Route 112. Talk to the Team Magma Grunts who are blocking the entrance to the Mount Chimney car station. Talk to them; they will tell you that the rest of Team Magma is heading to Fallarbor.
Go to Fallarbor Town and talk to the assistant in Professor Cozmo's lab. Head west to Meteor Falls. Defeat all of Team Magma. Go back to Mount Chimney and use the car station chairlift. Fight Team Magma to obtain the Meteorite.