Either hand wire board according to schematic/diagram on GitHub readme or print the EAGLE PCB project also on the Github repo https://github.com/ansonl/FordACP-AUX .

Open Ford_AUX_BLE_control.ino located in Sketch/Ford_AUX_BLE_control and upload to Arduino UNO.

If you are using a non Atmega328 chip board, you may need to modify the switchPin variable and PORT constants in the Sketch files. You can read more about this at http://ansonliu.com/2017/09/ford-acp-cd-changer-emulator-aux-audio/.