I have quite a few times now and it’s pretty simple. First install the SSL certificate for the site. Then put this in your WP-CONFIG.php right before /* That’s all, stop editing! Happy blogging. */
define(‘RELOCATE’,true);
Then login to your site while being sure to include https in the site address.
WordPress will automatically update your site url to https. After that is done, be sure to remove define(‘RELOCATE’,true); from your WP-CONFIG.php. Inside your WP-CONFIG.php, look for the database name and make a note of it. You will need that to update a few records in phpMyadmin.
Next step, if you have access to phpMyAdmin, open phpMyAdmin and locate the database you just took note of. Find WP_OPTIONS table and change locate siteurl and home. If either of those still have http, simple click the value and update it to https. Next, go to the WP_SITEMETA table and change it to https as well under siteurl.
If you are using WordPress Multisite with Subdomains and a Wildcard SSL Cert, you will need to do the same for all of the sites in the network. The all have a unique ID number assigned to them so it should be fairly simply to update them.
On the downside, if you have an existing site with tons of posts, you may need to use a search and replace plugin to update all the embedded links from media library items and links, etc.
I hope this finds you well. Have a good one.
