title: R - how to replace parts of variable strings within data frame
body: <p>I have a dataframe df:</p>
  
  <pre><code>var1 var2
  "test" "testing"
  "esten" "etsen"
  "blest" "estten"
  </code></pre>
  
  <p>Now I want to delete all "t" inside df to get:</p>
  
  <pre><code>var1 var2
  "es" "esing"
  "esen" "esen"
  "bles" "esen"
  </code></pre>
  
  <p>How do I do that?</p>