1. Remove the power unit that is in your QX4, keeping tract how in general the unit is mounted so you have an idea how the new one is to fit.

The unit is held in by the outside trim nut, where the mast comes out of the SUV, remove it with a small needle nose pliers by sticking the nose of the pliers into the slits of the nut and turning counter clock wise.  Next remove the splash pan from under the fender, the splash pan is held in with clips and screws.  There is a bolt at the base of the power unit, remove it. The large black reception and power supply wire is connected from the power unit to the radio, so you will need to remove the glove box and get to these wires and disconnect them there.  Once this is done then you can remove your old power unit.

MOUNTING:

2. Pull off of your original power unit the cast head that mounts under the front fender and install it onto the new power antenna.

3. Next remove the lower bracket from the old power unit and mount it to the bottom of the new power antenna, OR you can mount the bar bracket that came with the kit and mount one end of it to one of the lower tabs and after you install the unit bend it to where the original bracket was bolted to the chassis and bolt it tight.

4. Now install the power unit into your QX4, using your original outer black body trim and fasten it with the New Nut that was supplied. After the outside has been tightened then tighten the lower bracket to the chassis.
 

ELECTRICAL:

5. At the plug where your Factory Power unit was plugged into, cut off the square plug and then connect the three wires to the wires that are on the new antenna as follows. .... First you will need to connect the RED wire from the New Power Unit to the WHITE wire from that factory harness.  Then connect the GREEN wire to the GREEN wire from that factory harness. The Black wire is connected to the Black wire in that factory harness.

4. Connect the reception wire that runs to the radio, the large black wire from the new power unit. Other than putting the splash pan back, your New Power Unit will now Work.