I think you did not get what I have said to you, kuang.
I'll name the terminals.
Switch -> Has 3 terminals. A, B, C. From Left to Right.
Potentiometer-> A,B,C. From Left to Right.
DC + jack -> Fuse -> Switch B.
Switch A -> DC + Input.
DC - jack -> DC - Input.
Audio + Jack -> Potentiometer A terminal.
Audio - Jack -> Potentiometer C terminal and Audio - input.
Potentiometer B -> Audio + input.
Led: You'll have to add a 1.2k resistor:
Switch A --- 1.2k resistor ---- Anode
Cathode--- DC -
Look at the led base. Cathode is the flat spot.