The easiest way to send a 410 Gone status for an old WordPress page without editing server configuration files is to use a WordPress plugin. There are various plugins available that can help you manage redirects and status codes, like "Redirection" or "All in One SEO".
Here's how you can do it with the Redirection plugin:
Install and activate the Redirection plugin in your WordPress dashboard. You can find it by going to "Plugins" > "Add New" and then searching for "Redirection".
Once the plugin is activated, go to "Tools" > "Redirection".
Click on the "Add New" button to create a new redirection.
In the "Source URL" box, type the URL of the old WordPress page (the one you want to send a 410 status for). It should be the path after your domain. For example, if the old page was http://www.yoursite.com/old-page/, you would put /old-page/.
In the "HTTP code" section, select "Error (410)".
Click the "Add Redirect" button.
Now, any time someone tries to access the old page, they will receive a 410 Gone status, indicating that the page is permanently gone.
Always remember to check whether this process interferes with your website's other functionalities. Also, it is always a good idea to maintain an up-to-date backup of your website before installing new plugins or making significant changes.