I'm a job hunting author and expert who's also taught a wide variety of things over the years, including MS Word. The problem you're having could be caused by a bunch of things. For instance, the file is set as read-only, which means you can look but not touch. And that would be my first guess as to what's causing your problem.
The simplest workaround I suggest you try is to open the file in MS Word and then do a Save As. This will allow you to resave the file with a different name. That new file will be editable, meaning you can make whatever changes and updates you'd like.
I'm a job search expert and author who's helped lots of people with their searches, career choices, cover letters, resumes, and interviewing. I've also taught job hunting and subjects from literally A to Z. Plus, I've provided helpful advice to attendees at job fairs. In addition, I've done many job search workshops. And I have degrees in business and human resources.