Sorry I can't get any pics of the thermostat that I attached to the tank itself but here's the basics.
Here's the outside view, the element goes in through the drain, the wires run through the side through a hole I drilled.
From there there's some connections to the thermostat controller, you cut a little of the insulation away and stick it right to the tank.
I then ran to the backside of a plug, i make a jumper and plug off it to connect the heater power. I simply measured where it was on the inside, removed it and used a hole saw to make an access hole.
Using the same access I mounted a switch plate above the plug to mount the switch for the element.
I honestly can't say enough good things about this kit. This was my second one, both worked great. Once they've heated the tank I have no problem getting enough water to bathe a toddler. When the grownups shower I just add the propane.
It's nice just having hot water at the ready, especially is you're at a site and the power is included.
EDIT - Sorry the photos are all rotated wrong. Apple phone