There is a video on youtube for r6 windshield replacement. Exactly what I did. Pop the 4 plastic screws and pull up on the OEM windshield to remove. Takes some force to remove, but installing new one just slides in. This is the video I followed. Also installed the dark smoke zero gravity windscreen. Might be a bit different if you are installing a different brand.
I have the smoked sprint screen from yamaha shop. I had to remove the mirrors, it was tough enough getting the original out and about the same effort getting the new one in. I wouldn't have been able to do it without removing the mirrors, it felt like something was going to break when I had the mirrors on trying to remove the original screen.
There’s definitely a tab on the Yamaha R7 smoke windscreen that’s goes before the mirrors like the stock clear one. I installed the Yamaha smoked one and it would have never went on if I didn’t remove the mirrors.
It’s easy enough to remove the 2 nuts per mirror to remove them so you don’t break something.