Find the template and remove the whole row from the table. To find the template to modify, do this - vboptions > General Settings > Add Template Name in HTML Comments > set to Yes . Then go back to your page and view the source code and you will see the name of the template called around your part of the code.
Or, this may help -
How To Change The Ordering Of The 'Last Post', 'Threads', And 'Posts' columns