Do you have access to your server? If yes:
You can change your php.ini file with your terminal like. (check your php version first with phpinfo() to find out which php.ini)
sudo nano /etc/php5/apache2/php.ini
The default lines that control the file size upload are:
upload_max_filesize = 2M
Change this default value to your desired maximum file upload size. For example, if you needed to upload a 30MB file you would change these lines to:
upload_max_filesize = 30M
When you have the php.ini file configured for your needs, save the changes, and exit the text editor.
Restart the web server to enable the changes. For Apache on Ubuntu 14.04, this command will restart the web server:
sudo service apache2 restart