Before printing, you should have already:
.x3g fileNavigating the Menu:
Use the direction pad to navigate the menu.
Press the left arrow to go to the previous screen.
Menu Sequence: Down → Preheat → 
Press 
Printer will begin to heat extruder head to 230°C (default setting). Do not touch the extruder head with your bare hands.
Press the left arrow to exit to the main screen.
Menu Sequence: Utilities → Filament Loading
Select Load and press 
When the extruder head is hot enough, you will hear a tone. Filament will begin to flow out of the extruder head.
Once the flow is constant, press
(not the left arrow!) to stop the loading procedure.