Bought a carbon diffusor that doesnt fit lol

I waited two months for this to come in and the day it did I went to install it. It fits the car, goes on perfect BUT this is how the exhaust openings look. Obviously thats an issue and the stock the tips. They then told me I need to buy these exhaust tips from them to fit (which I did) but im not sure they are going to fit either. As for the protruding piece of the car thats visible in the exhaust opening, they recommended I cut it out to fit the exhaust. I have no clue what to do lol