I had struggled with this issue quite a lot initially until i stumbled upon the best solution.The max file size is defined in php.ini file and at times its quite a hassle to locate that file in the file structure. However there are two ways you can solve the issue. The first one below is the easier one out of the two
1)Log in to cpanel
Scroll down and go to software and select “Select PHP version” to arrive at a page that list the PHP extensions
In the upper right corner, select “Switch to PHP options” . Here you will see all the options including max file size that is allowed. The default is 2MB for the max file size, click on that option and change the size to 16,32 or 64 MB.
Viola! You are done
2)Log in to cpanel
Create a dummy php.ini file in the local machine and and put the below lines
upload_max_filesize = 64M
post_max_size = 64M
memory_limit = 400M
file_uploads = On
max_execution_time = 180
Upload this file in the root directory (public_html) through the File Browser in the cpanel interface.
One of the above two solutions should definitely work, at least in my limited experience they always have.Cheers.