Bottom right of that last picture. There is a metal bracket holding the black tank. I actually have it zip tied to the top of that bracket. Actually fits quite snug in that spot, so I'll probably keep it there.
And to get the original sensor clips off, I used a small flat head screwdriver and inserted it from the top to release the connector. This seems to be the easiest way, and so long as I continue to be careful, hopefully I don't break one..
