1

First Step

Login to your Wepwawet Control Panel
2

Second Step

Select your Server
3

Third Step

Make sure to Turn OFF the Server
4

Fourth Step

Under the General tab, Click on Files, Then select world, world_the_nether and world_the_end and click on the Delete button at the top.
5

Fifth Step

After that, Head over to General tab, Click on Console and Start the server.
There you go! You have reset your server’s worlds!