Start a new model on your transmitter.  Select H-1 for swash type.

Plug in the 7.4V power supply to the adapter.

Plug in the USB to serial adapter on the main controller and plug in the other end to a USB port on your computer.

Power on the adapter.

At this time both red and green LEDs should be flashing.

Start up the XP Configure software.  The software should automatically connect with the main controller.

XP Configure 1.2.2 tabs.

To start the setup click on Wizard on the toolbar.

Warning page.  Click NEXT

Select the main controller's orientation.  "Forward" for my setup.

For the Offset values these must be the distance of the main controller and GPS from the center of gravity (CG).

Click "Write".

NOTE:  Do not confuse this with the Cartesian coordinate system.

Entering the values in Step 2 should be as shown. 

On the Z axis "up" is negative and "down" is positive.

Here is how DJI recommends to find the center of gravity (CG) of your helicopter.

Remove the main blades.

Hold the helicopter vertically with the nose pointing downwards.

Drop a plumb-line (see plumb bob indicated by the arrow) beside the tailboom.  This is the X axis or horizontal line.

For Z axis, or vertical line, balance the heli on the skids.  I normally grab the tip of the head and see which direction the heli drops.

Mine was set up so the CG falls perfectly inline with the main shaft.

My CG intersects just below the tailboom.  Inline with the main gear.  About 12cm from the main controller.