Hi Azfar,
Apparently you missed the iFixit guide specifically made for removing and replacing the wireless charging coil for your phone. It's right here.
[guide|135921|Google Pixel 4 XL Wireless Charging Coil Replacement - iFixit Repair Guide|new_window=true]
I'm not clear what you mean by the rear camera cover; all the replacement frames I've seen online come with the rear panel already assembled with the camera mounting parts and lenses. I did note that the flash/microphone/sensor assembly needs to be moved over from the old panel to the new one; is that what you're referring to?
If so, I didn't manage to find any guides to that particular replacement, but I checked and it appears the standard Pixel 4's rear panel assembly is very similar so I'm fairly confident the available guide for that will be sufficient to enable you to replace it on your 4XL. Here's the guide.
[guide|136218|Google Pixel 4 Flash Assembly Replacement - iFixit Repair Guide|new_window=true]
Good luck with your repair; let us know how it goes!