- Install the latest non-beta arduino software IDE/toolset: http://www.arduino.cc/en/Main/Software
- Download the Marlin firmware - Latest developement version - Stable version
- In both cases use the "Download Zip" button on the right.
- Some boards require special files and/or libraries from the ArduinoAddons directory. Take a look at the dedicated README for details.
- Start the arduino IDE.
- Select Tools -> Board -> Arduino Mega 2560 or your microcontroller
- Select the correct serial port in Tools ->Serial Port
- Open Marlin.pde or .ino
- Click the Verify/Compile button
- Click the Upload button. If all goes well the firmware is uploading
That's ok. Enjoy Silky Smooth Printing.