How to replace iPhone 8 flashlight positioning ring

Hi everyone,

I am just attmepting to transfer all the components from one iphone 8 to a new housing and I mistakenly got the new housing which didnt have the smaller components already installed -

I am wondering how I transfer the flash light positioning ring to the new housing when it has no adhesive on it.

Do i just sit it in there? Or do i need to buy a new one (which has adhesive already on it? Or do i just buy some adhesive and put a spot of glue on it?

If I just buy some, which adhesive should I get?

Any advice greatly appreciated

Thank you

Eden. (It’s my dads account)