Simple! All you have to do is edit the .htaccess file found in your root Wordpress directory. Simply take the below code and paste it right above the # END WordPress line and save. The next time you go to the import page in your WordPress dashboard, you’ll see 20 MB as the new file size limit.

You can edit this to be higher if you want. 20 MB should be enough for just about any import, but you can adjust this to suit your needs.

php_value upload_max_filesize 20M
php_value post_max_size 20M