How to replace plastic hinge cover?

The plastic hinge cover has broken on my Asus X555LA laptop, so I have ordered a replacement. Can someone please tell me how to put the replacement in without damaging it. I'm not sure which way around to put it in and forcing it the wrong way will break the plastic teeth. I know to have the laptop cover open but am unsure which way round the cover fits and whether it slides into position etc.

Thanks.