Are you just running the stock MakerFarm firmware? If so... You probably would just download it... And install Arduino from Arduino.cc. You would then double click on Marlin.ino . You would set your board type and what serial port the board is on (with the USB cable connecting the board to the computer).

Then click Ctrl-U to compile and upload the firmware.

PS. I don't have a MakerFarm printer. But those steps are going to be very similar for any RepRap printer that uses Marlin firmware.