How to get rid of duplicate content?

How to get rid of duplicate content?

Here are the three ways I recommend.
The rel=canonical tag. In most cases, the rel=canonical tag is the best way to transfer SEO juice from a duplicate page to another page. ...
301 redirect. Sometimes, you don't want the duplicate of your web page to stick around. ...
Set passive parameters in Google Search Console.

First, search & then replace :D :)

You should have to replace old content with new to fix this issue.

There are four methods of solving the problem, in order of preference:
Not creating duplicate content.
Redirecting duplicate content to the canonical URL.
Adding a canonical link element to the duplicate page.
Adding an HTML link from the duplicate page to the canonical page.

Not creating duplicate content.
Redirecting duplicate content to the canonical URL.
Adding a canonical link element to the duplicate page.
Adding an HTML link from the duplicate page to the canonical page.

In many cases, the best way to combat duplicate content is to set up a 301 redirect from the "duplicate" page to the original content page.

Only add unique hand-written content to your web pages.
Don't add content to your pages that is found verbatim on other pages on the web.
Do not 'spin' text on pages on your site.
Don't create thin-pages with little value add to users.