This is pretty easy.  Look at the cylinder you are going to replace this one
with (you have a replacement right?).  Measure on it where the tab is and
drill.  Then press the tab with a nail or pin of some kind and pull the old
cylinder out.  Shouldn't take you more than 5 mins.  Hope this helps.

Thanks,
Ken Wilford
John 3:16
www.vanagain.com
Phone: (856)-765-1583
Fax: (856)-327-2242