Pull the rear side plastic and that one little plastic piece under the front of the rear rack and you should have it. However I'm
not removing my rails to prove it. I could be wrong if any of those bolts are going into nuts instead of threaded frame holes, in which case more may need to come off to access the nuts and keep 'em from spinning. But I think you'll be OK.
The Givi mount 'arms' are going to the steel sub frame not the plastic. (Brian I know
ZedHed put you up to this, now cut that out.
)