I've got a Hotbodies undertail, but I'm using Proton front blinkers.
I'm including a link to some photos I made while installing my undertail.
Unless they've changed, the instructions from Hotbodies sucks how they show cutting the fender.
The best (but not the easiest) way to trim your fender is to remove it from the bike.
Otherwise you may not get a clean cut.
Also, I had to trim around undertail section that surrounds the ECU well to fit the fender using a dremel tool.
For the front blinkers, I used the wires and connectors from the stock blinkers and soldered/shrink-wrapped onto my flush mounts. They supported the stock running light, so I have both connectors used.
Here's the photos showing my undertail installation.
Supposedly Hotbodies states their LEDs are brighter than before.
Let us know that that's true. That's the main disappointment I had with their undertail.