Well I made the mistake of ordering the 19" forestor kit, but this should be the right one..
OLM JDM Precision LED Lift Gate Light - 14-18 Forester, the light fits perfect into the opening.
Also if you follow the video on the site of how to take it apart, it is pretty close on everything, on the side with the cargo light, there are 3 screws, one behind a cover (round up high) and this is also next to a round fitting which I believe holds the cargo cover when extended, which has the other screw in it, these are literally two inches apart, the other one is behind the hook at the bottom of the panel.
Also the handle on the actual hatch itself, splits apart in two and reveals the two bolts holding the main big panel on the hatch itself.
The rubber fitting that is ran in between the hatch and the body, don't take the rubber off the plastic grommet, reach in with a small flathead screwdriver and push the tabs (4) or as many as you can get to, these will release the rubber grommet and plastic grommet together so you can run the wires inside. Then when done, you can just snap back in the whole assembly.
If you run the harnesses like he says on the video this works well. though on the left side of the car.
The top panels (these have the seatbelts in them) these are the ones above the actual cargo light panel itself have hooks on the front of them, (the edge closest to the front of the car, and these panels are meant to have the back loosened (the edge closest to the rear of the car), and then pulled back towards the rear of the car.
I made the mistake of ordering the wrong kit and had to wire it myself, but I'm pretty sure this kit has the two-wire plugs and will work.
I also forgot, you have to remove the cargo tray just like in the video, it removes first, then you can get the sill plate panel off of the back, (the ledge panel at the back of the cargo deck, lol how else to describe it? then when your done, you have to put that panel back in first, then the cargo tray, it clips in the front, side and into that back sill plate.
Thanks for wu01ok for reminding me..