title: Remove line numbers at the start of each line
body: <p>I have numbers at the start of each line in my text file in the following format :</p>
  
  <pre><code>1: text written ....
  2: text written ....
  </code></pre>
  
  <p>which continues upto 973 lines.<br>
  I want to delete any starting numbers with a space and a colon after it ...
  How do I do it using regex in Notepad++ ?</p>