You might have heard that you may need to edit php.ini to change Post Max Size and other important variables for wordpress but there is no need of it as you can add the below line of code either to functions.php in your theme file or in my custom php functions plugin (which takes care of adding all your functions to functions.php)
@ini_set( 'post_max_size', '64M');
The above code sets the maximum post size to 64 M