The PMC-55 is a doable installation but there are a few tricks to making this work properly. Thank you to DJ Nole Love for providing the pictures! Feel free to reach out to Nole Love directly if you are interested in doing this type of installation and want to have a professional repair tech do the job.
Since there isn't enough voltage on the crossfader connector itself to run the Innofader, you'll need to locate power inside the mixer and hook up wires. You'll find the "Power I/O Cable" inside the Innofader Pro2. Here's a picture including the Power I/O cable.
On one side of the Power I/O cable, clip off the connector and strip the wires. Locate the power supply inside the mixer according to the below picture. A red pen mark shows where you solder the red wire, and and black pen mark shows where to solder the black wire:
After you solder the wires, it will look something like the below picture. ***When you are done, please cover the wires with electrical tape to prevent them from short circuiting inside the mixer!
Now for the crossfader connector, simply hook up adapter 3. One end goes to the mixer crossfader connector and the other goes to the Innofader Pro2 crossfader connector:
Now for the mechanical fitting, use a drill to make two countersunk holes on the crossfader plate. These holes are for mounting the Innofader Pro2. They should be spaced 65mm apart center to center. When you are done, the fader plate will look something like this:
And before you hook up the Innofader itself, use washers to lower it to the proper height: