1. Create php.ini file inside your public_html folder, OR the folder in which you have installed your script, and paste the following code into it:
disable_functions = allow_url_fopen, escapeshellarg, escapeshellcmd, ini_alter, passthru, parse_ini_file, popen, proc_open, proc_close, proc_terminate, proc_get_status, proc_nice, readfile, show_source, system
If you already have the disable_functions line, just append the code to match what is above.
2. Open .htaccess file inside your public_html folder and append the following line:
where username is your Cpanel username. In case you don't have .htaccess file there, you need to create it.
The most popular and easy ways to create/edit files inside your account are FTP clients or Cpanel File Manage