Payment gateway with integration instruction

[kenyanprince]

I am currently working on implemeting a payment system using a company that does the payment processing called Pesa Pal
They offer the instructions, php files but have no idea how to implement this in virtuemart on joomla.
The company is called Pesa Pal and the link is as follows https://www.pesapal.com/home/integration for the integration.
Please guide me on how to get this working for my site.
Thank you