There are a few different methods to installing the ImmersionRC rapidFIRE into the FPV goggles. 

For the HDO, Attitude V3 & V4 it's plug and play. However for other older Dominator goggles you need to modify them in order to handle the high current demand for the Rapidfire.

There are two ways:

• Using the Auxiliary Power Board
  
• Modifying your Goggles
  

Using the Auxiliary Power Board

The Rapidfire comes with a ribbon cable for you to connect between the auxiliary power port on the rapidfire to the head tracker bay.
It's a pretty easy thing to do, but the ribbon cable will run across the front of the goggles, and it's not the most neat solution.
Please refer to the manual for instructions.



Modifying your Goggles

The other thing you can do is to modify your goggle. It requires soldering on the PCB board inside your goggles. Here is a demonstration video.