Upgrading from 2.2.3 to 2.3.0

-- url of the page with the problem -- : morenadancewear.com.au/ and salsashoes.com.au/
-- HikaShop version -- : 2.2.3
-- Joomla version -- : 2.5.19

I am having a problem updating my two Hikashop versions from 2.2.3 to 2.3.0, is there anything that need to be done besides downloading the latest file and upgrading? I am getting error for both websites.
Regards.

Hi,
And can you try to install it via FTP ? If it still not working, can you give me more information about the error that you are having ?