Can you post some photos of what you have?
It attaches like any 3-point implement. You can put on the pto pump first then use the BH controls to align it most of the way.
The upper link is special, made to resist bending, and that one should be used.
And down where the tractor's arms attach, there is a side to side bar that belongs under the 3-point arms. It keeps the BH from rotating around its pins. This is a safety measure that prevents the hoe from rising suddenly if the bucket slips off a root etc.
This is a lightweight hoe sold by the Kubota dealers specifically for your B7100 so it's well matched and I don't think you risk tearing the back out of the transmission.
I don't remember if I mentioned it in that referenced thread, but that same American-made hoe was also sold in Yanmar colors with a Yanmar trademark on it. My YM240 is the correct model for that one - or either color, actually, since they are the same hoe aside from the color.