Integrating a custom Payment Gateway on a premium wordpress theme

Hello, Basically, we're trying to integrate a custom payment gateway ([login to view URL]) into a premium wordpress theme, due to the fact that we're not developers we got stuck! This should not be more than a couple of hours job we hope. The theme developers provided us with a sample gateway plug-in files, and from the other end (the payment gateway) we have almost everything we need (Merchant ID, secret key, API sample codes, express checkout sample codes, [login to view URL] account, etc..). At this point, we need someone to guide us through how the integration process is done via Team Viewer on our local server for the following: - API Integration. - Express checkout integration. Attached you'll find : - Payment gateway plug-in from the developers of the theme. * [login to view URL] - Sample API integration codes from the payment gateway providers. * [login to view URL] * [login to view URL] - Sample express checkout codes from the payment gateway providers. (PDF) *[login to view URL] Thanks, Adnan M.