This article will cover the steps needed to upload an existing world to your Space Engineers server hosted by Host Havoc.
Step 1: Locate and upload your local world folder (typically found in C:/Users/YourName/AppData/Roaming) into the Saves folder of your server (\ServerSaveData\Saves\) using an FTP Client
Step 2: Once uploaded, click on the "Configuration Files" section in your game panel and edit the LastSession.sbl using the Config Editor.
Step 3: Change the "World Name" option to use the name of the world folder you uploaded to the saves folder and then save the changes.
Once done you can start your server.