How to replace the webcam?

You will have to basically completely disassemble the thing to get to it.

It'll take a properly sized screwdriver, a few guitar picks, sprudger, some iso-alcohol (to loosen the ridiculously strong glue strips holding the bottom of the screen bezel to the screen, gotta go slow and steady to get it loose.

I acquired a water damaged unit from a friend and ended up taking it to bits. If I recall correctly, other than removing the various screws in the way, I popped the bottom plate off, removed the battery, took out the heat spreader, unplugged everything (lift the black latches for some of the ribbons, for the screen lift the bar and slide it out, pull all the screws and remove the main board, pop the hinge panel across the back off, undo the hinge screws and lift the monitor off. Now, you have to carefully (because there is zero support for the panel) work a thin guitar pick around the seam, the catches around the hinges are a pain, and at the bottom of the screen there are these double stick strips holding the bezel to the screen face, I used a soft plastic sprudger stick while avoiding pressing down or levering against the screen especially at a single point, drip alcohol down the sprudger not too much just a little to wet the edge, it took me about 10 minutes to slowly, SLOWLY, moving the sprudger from the side up and down like it pivots at the point working the glue, up towards the top of the screen and down towards the hinges, not back and forth away from the screen. Once that finally lets go and you can remove the bezel, its just lifting the black holder, remove the cable, a screw or two holding the camera/mic/LED/light-detector(?) module down.

Pop the new one in, screw it down, pop the bezel back together, remember to be mindful of where the cables lay, fish the cables back into the base casing, screw the hinges down, put the board back in, cables in place, a new boop of thermal compound on the silver CPU package, heat spreader, battery, bottom panel, sacrifice a chicken, cross fingers, and hit the button.

If you're not up to it, I don't blame you. I wrecked a bunch of stuff learning to repair things. But I'm willing to bet you know a capable nerd that will give it a go if you buy the pizza. You pay your repair nerds right? Some of us are fine with beer and pizza.... Just don't make us work for nothin 😉