After reading scalbert's thread
about Procede PNP power connections, I decided to take a few photos while tapping the external ground wire in the Procede V3 Rev I harness to wire 17 in the shaved small sub-connector.
Find the black small sub-connector with the shaved side.
Cut the end of the external ground wire
Find a 6-8 inch long wire and insert it to the tube that holds the wires going to the sub-connector
Attach the ground wire to the end of the wire using some tape and pull it through the tube
Take out wire #17 from the sub-connector using a small screw driver.
Create an area on the wire to tap the ground wire to. Instead of using an eletric tape I chose to use some heat-shrink tube as you can see in the picture
Tap the ground wire to the red wire. I chose to solder it with my poor soldering skills.
Insert the red wire back into the sub-connector
Thanks to scalbert for the information he provided at http://www.e90post.com/forums/showthread.php?t=191477