title: Rename dataframe columns based on values in another dataframe in R
body: <p>I have one data frame which has one column &amp; two records in it.</p>
  
  <p>DF1=</p>
  
  <pre><code>Name 
  M_D
  ABC123
  </code></pre>
  
  <p>I have another dataframe which has two columns. I need to rename second dataframe columns with two values in first data frame. </p>
  
  <p>DF2=</p>
  
  <pre><code>   PQR  LMN
     111  345
     456  999
  </code></pre>
  
  <p>I want DF2 as below </p>
  
  <pre><code>   M_D  ABC123
     111  345
     456  999
  </code></pre>
  
  <p>Thanks</p>