To change your servers difficulty, log into LYHMEPanel, select and stop your Unturned Server, then follow these steps:

1. Click on "Configuration Files

2. Click on [Text Editor] Across from Commands.dat  

3. the fourth row down, it will appear as the following.

mode normal

4.
 Remove "Normal" This can be Easy, Normal, or Hard

5. Once you are happy, click SAVE

6. Start your server