Magento Certified Professional Developer (For site migration)

Move the theme on magento theme to live New Magento site here (lastest Magento version) [login to view URL] [login to view URL] (Old site is version magento 1.7 We need to retain old customers order history and checkout and store information Once migrated full testing of the cart and site working order needs to be tested and working and confirmed no issues This task needs to by magento expert with plenty of experience