Book marketing: look at the book’s product page, first
Yes, you can change the title!
When I chat with authors, I’m often shocked at how few consider changing their book once it’s been posted. Why wouldn’t you change things, if the book isn’t selling? Always give your books the best chances to succeed.
So, change anything and everything.
TIP: only change one thing at a time. Otherwise you’ll never know what worked. If you spot obvious boo boos: bad title, incorrect categories, etc—change them at once. For minor changes, give your change ten days to kill or cure, then change something else. Make a list of potential changes.