Open by the PCB design for the main circuit. The file can be found here: KiCAD PCB Design File
In PCB View, go to Files -> Plot -> Gerber Files
Leave the defualt slected layers and press 'Plot'. This will generate the gerber files needed for manufacturing.
In PCB View, go to Files -> Fabrication Outputs -> Drill File
Leave the default selections and press 'Generate Drill Fil'e. This will generate the drill files needed for manufacturing.
In PCB View, go to Files -> Fabrication Outputs -> BOM File
Press 'Save'. This will generate the bill of materials files needed for manufacturing.
Alternativly, the bill of materials file can be found here: Bill of Materials
In PCB View, go to Files -> Fabrication Outputs -> Footprint Position Files
Leave the default selections and press 'Generate Position File'. This will generate the footprint position files needed for manufacturing.
Send all of these files to your PCB manufacturer of choice for manufacturing.