Intra prin cpanel si:
1. adauga in wp-config.php
define('FORCE_SSL_ADMIN', true);

2. modifica in .htaccess (nu uita sa schimbi yoursite.com !!!)

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]

RewriteCond %{HTTP_HOST} ^yoursite.com [NC,OR]
RewriteCond %{HTTP_HOST} ^www.yoursite.com [NC]
RewriteRule ^(.*)$ https://www.yoursite.com/$1 [L,R=301,NC]
</IfModule>

Tutorialul complet aici: https://designmodo.com/wordpress-https/