elecfreak display SD card

I am using Arduino MEGA2560 board with 7 inch Touch screen graphic display module from Elecfreak for my project.
It has a built in SD card.
Can anyone guide me how to use this built in SD card please ?
Many thanks for your support.
-Arun Karkare

According to the elecfreaks wiki for the product the SD card SPI is on pins 35-38 on the connector.