Wordpress - How to migrate a HTTPS WordPress installation to localhost?

This is because the site_url and homeurl of your original installation are set to HTTPS in the database, so you can't access your website on localhost unless you:

1. Change these values to non-ssl
2. Install a SSL certificate on localhost

I will only explain the first case since installing a certificate is out of this community's scope.

To do this, you have 2 options.

Directly edit the downloaded SQL file

Open the MySQL export that you just downloaded from your server. Search for wp_options and you will find a line in your database like this:

INSERT INTO `wp_options` (`option_id`, `option_name`, `option_value`, `autoload`) VALUES

The 2 lines below this one are siteurl and homeurl. Change both of their values to http://localhost/. Pay attention to quotes and commas! So, the 3 first line will look like this:

INSERT INTO `wp_options` (`option_id`, `option_name`, `option_value`, `autoload`) VALUES
(1, 'siteurl', 'http://localhost/', 'yes'),
(2, 'home', 'http://localhost', 'yes'),

Then upload your SQL file. That's it.

Update the values by PHPMyAdmin

If you have PHPMyAdmin installed on your localhost, or you have enough knowledge to directly update the tables via command line, the proceed with this method.

Login to your database by PHPMyAdmin. From the left navigation menu, choose the proper database. Now, select the wp_options table from the right section.

Again, the two beginning values will be siteurl and homeurl, which you can simply update to http://localhost/ without worrying about making a mistake by editing the original SQL file.

In the wp_options table, you will find two rows that have the site URL. Change those two values.

Your media and other links to internal pages might have to adjusted, though. That's why I let the great WP Clone plugin (https://wordpress.org/plugins/wp-clone-by-wp-academy/ ) do all the work for me. You just install the plugin on the source system, back it up, then install the plugin on the target system, and restore.

Great plugin, takes all the work out of moving (cloning) a site. I sometimes have to do the restore twice (the first fails for a mysterious reason), but the retry works just fine. All data, users, content, etc moved very nicely.