title: replace number after underscore
body: <p>I nee to replace all numbers after underline inside a string.</p>
  
  <p>I think that I can use Regex, but I don't know how to use Regex Syntax</p>
  
  <p>See an example of my string:</p>
  
  <pre><code>milton_0
  milton_1
  </code></pre>