Edit HTML, Very basic question. Options

[EL Dusty]

On a website I need to edit this:

<a href="https://twitter.com/xxxx" class="newwindow" target="_blank" rel="noopener noreferrer"><img src="/sites/abctales.com/themes/abctales_new/images/twitter.png" alt="Follow ABCtales on Twitter"></a>

I need to change that to

<a href="https://twitter.com/yyyy" class="newwindow" target="_blank" rel="noopener noreferrer"><img src="/sites/abctales.com/themes/abctales_new/images/twitter.png" alt="Follow ABCtales on Twitter"></a>

Firefox web developer tools seem unable to save the change. (I have superuser privileges on the site, but there’s no-one else to sort it. It’s a charity site)

Anyone able to give an idiot an idiot proof walk through?

[Christian J]

Firefox web developer tools seem unable to save the change.

Those tools only make changes to the page copy you see in your own browser.

To change the public website you need to edit the relevant HTML file hosted on the web server. If it's another file format (like .php) you should probably ask the one creating the site for guidance.

You can download the file from the web server with an FTP program (FileZilla is free and good), edit the file in any text editor, then upload it with the FTP program to overwrite the current file on the server (make a backup copy before overwriting anything).

I have superuser privileges on the site

Not sure what this means in this context. Does the site use some kind of blog software? If so the above may or may not apply.