Convert Amarok to be powered by USB

I would like to convert my Amarok to be DC only power. I believe I will need to cut the DC side of the power cable. According to the manual, the 4 wires are 2 grounds on the bottom and 2 hot lines on the top. Per the attached image, can I connect my negative lead to 1 and my positive lead to 4 to power the device? If not, using a positive wire and negative wire, which 2 wires will power the device?

I think you are right as it is the same as in the picture.

USB only gives you 5 volts so I don’t think it will work.