Add this code in htaccess:
php_value upload_max_filesize 20M
php_value post_max_size 20M
php_value max_execution_time 200
php_value max_input_time 200
You can increase the file upload limit according to your requirement.
OR
Save this code in any php file and update it in the plugins directory and activate that plugin:
ini_set(‘upload_max_size’,’256M’);
ini_set(‘post_max_size’,’256M’);
ini_set(‘max_Execution_time’,’600′);
OR
So here are the proper steps:
1) Use FTP to download a copy of your php.ini file
2) modify that file to have the following lines:
memory_limit = 100M
upload_max_filesize = 192M
post_max_size = 100M
file_uploads = On