Replacement is really the best option and consider it a lesson learned. It is possible that drilling the side also damaged the plates. If you choose to attempt a repair, a good acid resistant epoxy will do the job, do not plug the hole with a screw as the screw will hit the plates. You will need to get battery acid to refill the cell and you may need to adjust the concentration depending on the state of charge when the electrolyte leaked out.
 
Dennis > Date: Sun, 28 Dec 2008 14:28:59 -0800> From: djct2@YAHOO.COM> Subject: fix hole in battery> To: vanagon@GERRY.VANAGON.COM> > Is there a way to repair a hole I my battery, I drilled a 1/8 in. hole in> the side of my battery near the bottom by mistake, is there anyway to repair> it. I thought of epoxy and a screw? If not any recommendations for a> replacement. dj