How to replace Camera with Camera2 in PCL Custom Renderer project?

Hello,
I'm creating an app which is supposed to have a custom camera. What I need is to display some custom text and buttons over the camera preview. I downloaded a sample which works in IOS and also in Android, however, for the Android part, it uses the old Android.Hardware.Camera, so the newer APIs won't run that. I would like to replace the Android renderer's Camera with the newer Camera2, since I'm targeting API 27. Does anybody have an idea on how to do that? I've already done research and tried all sample project I could. Including the official Camera2Basic and Camera2Raw samples...
these is not for a PCL project and I'm not able to "copy" that to my project...
All I could find was either in Xamarin, but not PCL, or written in Java - not usable for me.
PLEASE HELP! Thank you!