Combining 2 PHP Scripts

Hi , we have already purchased 2 php scripts and the task is the COMBINE both scripts to 1 Dashboard , remove un necessary Options , Share the USERS profiles getting created from Front end etc. It about combining a Ticket Support System and Invoicing System. Kindly note we need SMS Gateway integration using one of Australia's popular SMS gateway when ever there is an Invoice raised by admin and when ever there is a reply from Admin to a support ticket. Certain files are obfuscated, but we do have developer licence

Maximum time we can allocate is 5 days