title: Renaming multiple levels - change "man", "Male", "M" into "male" in R
body: <p>I'm handling a dataset which contains a gender column with messy data. I'd like to change "man", "Male", "M" and "MALE" all into "male". </p>
  
  <p>Is there a convenient way to do this such as grouping them together and assign them the same new name "male"? I tried several packages but none of them could assign one new name to multiple old names.</p>
  
  <p>Thank you so much!! This is the final project of my first semester :)</p>