1. Stop your server
2. Click Files
3. Click Backup
4. Click start
5. Green box will appear at top of screen saying backup done and ready for download (This can take some time if the world is large)
6. Click on the Multicraft FTP client (is it underlined)
7. Login
8. You should see a listing of files
9. Find the .zip file (world.zip) and click on it for downloading. Note if the zip is large you might need to use an FTP program such as filezilla to download it.
10. Once download is complete, restart your server