After looking at the diagram, the instructions seem to follow what I did on during my Hotbodies undertail install.
What you want to do is make a square "U" cut on the fender to preserve the fender sides.
This is so you preserve the relay mount tabs and the fender mounting points.
Hotbodies has you zip-tie the relays to the sub-frame which is utterly stupid and lame.
Then I used scrap plastic from the fender to fashion support tabs for the undertail, rather than have it flop about at the rear.
This makes for very good fit with the rear cowl.
Here's where I attached the under tail support tabs to the fender.

What you want to do is make a square "U" cut on the fender to preserve the fender sides.
This is so you preserve the relay mount tabs and the fender mounting points.
Hotbodies has you zip-tie the relays to the sub-frame which is utterly stupid and lame.

Then I used scrap plastic from the fender to fashion support tabs for the undertail, rather than have it flop about at the rear.
This makes for very good fit with the rear cowl.

Here's where I attached the under tail support tabs to the fender.
