upgrade from Joomla 2.5 to Joomla 3 what about the template?

Hi,
I work on a local copy of my website to install configure and use Storefront template (This is to change the actual template I don't want to use anymore)
So as my website is Joomla 2.5 running, I installed Stoefront for J!2.5 and that worked well.
Today I upgraded my local copy from 2.5 to J!3 and Storefront doesn't work anymore
How can I replace the J!2.5 version with the J!3 version ? Do I have to uninstall first ?
Thanks

This is the errot I have
(error : Fatal error: require_once(): Failed opening required '/Applications/MAMP/htdocs/mywebsite/templates/gk_storefront/libDSframeworkDSgk.parser.php' (include_path='.:/Applications/MAMP/bin/php/php5.4.10/lib/php') in /Applications/MAMP/htdocs/mywebsite/templates/gk_storefront/lib/gk.framework.php on line 16)

Hi,
you're "Expert Boarder" so you should know that you have to update also template to new version not only CMS

Hi Oscar,
shame on me...

Probably you were tired.
Please do not forget about modules also.