Replace broken back lens cover

Hey there,

My Pixel 3’s back lens cover is broken. I’ve ordered what seems to be the replacing part :

https://fr.ifixit.com/Boutique/Android/G...

Problem is, the lens is too big, as you can see on this little video : https://youtu.be/B1JFWfkVJx4

Do I have to remove all the backpanel to change it from inside ? I hardly doubt it, and customer service at iFixit does not know…

Thanks a lot for your help