In an .htaccess file in the KBPublisher installation directory change and uncomment line:
For example, if the desired filesize is 3 meg, the following directive would be placed in the .htaccess:
php_value upload_max_filesize "3M"
You also may want to change the following directives:
If you are on windows with IIS server .htaccess file will not work for you,
You should update these settings in php.ini file.