In order to rename a file of the directory you need, when logged in as an administrator, to click File Manager in the menu.
Click the Rename File  button. In the File Name field, enter the new selected name. 
Select one of the following options:
R: Check R to make file read only
H: Check H to make file hidden
S: Disable hidden option in file properties (Windows)
A: Allows file to be archived by the operating system.
Click the Save Changes  icon to rename the file.