How do you get rid of the wailmer blocking route 124 in Pokemon ruby?

You can't get rid of the Wailmer blocking Route 124 in Pokemon Ruby! This is a plot point and is meant to be a roadblock until you advance further in the story.

Here's what you need to do to get past it:

1. Continue the story. You'll need to progress through the game, specifically dealing with the events in Slateport City and the subsequent developments at the Slateport Gym.

2. The Wailmer will move eventually. As you progress, you'll trigger an event that causes the Wailmer to move out of the way, allowing you to pass through Route 124.

Important: You can't battle the Wailmer or use any other methods to force it to move. It's an integral part of the game's story progression.