I tracked down your template and it was originally done by joomlaxe.com, which is kind of an informal template company in Indonesia. You'd be better off going with a more established company so you can get support on what you do.
It's not too difficult to update a template, but I'm getting the feeling that it could be a lot of trouble for you if you haven't taken our templating course. YOu should do that first if you are going to attempt it.
Otherwise, check our list of recommended developers and see if they can help you.
www.ostraining.com/resources/joomla/developers/ That would be the easiest route.
Whichever route you go, be sure you have backups and that you experiment on a test site, not your actual site. Get everything working in a test site before you go live.
Ed