^the way I did it was....try to put it in...what rubs? dremel it!
plug it up and your good to go. mine took a couple hours. OH youll need to mount it somehow...I had some solid mounts, but it got ripped out, so when the professional guys put in a new one, they used, a sort of tack strip, stuff I would use to secure ducting for microwaves/dryer vent/shower vents..etc and the screws have already fallen out so it rattles around