It is very easy to remove the back cover.

Take away the battery after power off the phone.

Peel off the warranty label.

There is a screw beneath.

Take away SIM cards and SD cards if you have any.

Pry off the back frame with a piece of plastic card.

Remove the broken front camera.

New front camera from witrigs Make sure the front camera connects to the motherboard well.

Install the back frame.

Install the battery.

Power on the phone.

Open the camera and switch to the front camera.

Test the front camera by taking a photo.

Power off the Phone.

Source: Youtube