I've watched the video which makes it seem easy.
But they really don't talk much about the hard part which is routing the line back to the FW tank or the non-pressurized side of your water pump. All the video shows is hooking up the diverter, which is the easy part. And the guy in the video uses a regular drill bit and cracks his shower liner, they conveniently hide this behind bold lettering that says "USE A HOLE SAW" When I watched the original video which was posted for a while before they superimposed the bold lettering, you could clearly see the guy cracking his shower liner with his drill bit.
installation video link here