<i>Not</i> by trying legal actions to make the defamatory content go away (google the Streisand Effect to see why). This includes legal actions to get the site to remove the content.<p>Instead, you have to fight it with facts and evidence, in public. Or else you just have to ignore it.
If you are European or Argentinian:
<a href="https://en.wikipedia.org/wiki/Right_to_be_forgotten" rel="nofollow">https://en.wikipedia.org/wiki/Right_to_be_forgotten</a>
I wrote a long comment, then decided to turn it into a blog post cuz I know a good bit about the subject:<p><a href="http://michelerebooted.blogspot.com/2017/10/how-to-deal-with-internet-defamation.html" rel="nofollow">http://michelerebooted.blogspot.com/2017/10/how-to-deal-with...</a>