I have setup a WP Multisite a year ago. All went fine, I was happy with the setup. However, the main domain that I was using to access the admin panel is no longer in my possession (domain expired and bought by someone else). How can I access the admin panel of the sites included in the multisite setup now that domain is gone? The admin page is not opening for any of the sites (www.site.com/wp-admin/ redirects to the unavailable domain). Can I make some db or file changes in order to regain the access to admin?