Log in to Directadmin. If you are not sure how to get here, you can look in this guide.
Then navigate to System Info & Files -> File Manager

- Select the files you want to move
 - Click on the three dots at the top center
 - Press 
Copy/move to... 

Here you choose where your files should be moved or copied.
- If you click on the link, you go back one step in the folders and in this way you navigate to where you want to move the files
 - If you select 
Copy, a copy of the selected files will be created on the new destination - If you select 
Move, the files are moved in their entirety to the new destination 
