![Image](http://www.lasermad.com/instructions/CLK503/Instructions/503psu1.jpg)
Tin the 2 outer terminals of the USB plug:
![Image](http://www.lasermad.com/instructions/CLK503/Instructions/503psu2.jpg)
![Image](http://www.lasermad.com/instructions/CLK503/Instructions/503BAG21a.jpg)
Strip the outer insulation of the PSU cable back about 20mm then strip and tin the wire ends. Solder them as shown to the USB plug.
If you have a power supply with black and green wires use this photo:
![Image](http://www.lasermad.com/instructions/CLK503/Instructions/503psu3.jpg)
If you have a power supply with red and green wires use this photo:
Finally use the 2 black plastic housing pieces to finish the plug assembly.