it is a very simple operation that is performed in the same way as on your PC. Gamesclan does not recommend it but this is the procedure
1) stop the server from the panel
2) download the crack of your multiplayers game from the internet for the exact version of your game for example COD WAW 1.7 test it with an antivirus
3) read the instructions attached in the downloaded file
4) through the file manager icon of the control panel or via ftp save the original files of the server that will be replaced.
5) replace files
6) start the server at this point enter the server if everything is ok to play otherwise restore the original files and look for another working crack.