Ensure your Samsung Galaxy S3 is completely powered off. To do this, press and hold the power button and select 'Power Off' from the menu. Wait until the device is fully off before proceeding.

Using your fingers or a plastic opening tool, gently pry off the back cover starting from the top or bottom edge. Once removed, take out the battery by lifting it from the bottom edge.

If present, remove the SIM card and microSD card by gently pushing them out of their slots. This prevents damage during the repair process.

Using a Phillips #00 screwdriver, remove all screws from the rear housing. Carefully use a plastic opening tool to separate the rear housing from the front assembly. Be gentle to avoid damaging the plastic clips.

Gently disconnect the display connector using a spudger. Also, disconnect any other visible cables that might be connected to the motherboard.

Use a heat gun or hair dryer to gently heat the edges of the screen to soften the adhesive. Once heated, use a suction cup to lift the screen slightly and insert a plastic opening tool to gradually separate the screen from the frame. Take your time to avoid damaging the underlying components.

Carefully place adhesive strips or double-sided tape around the frame where the new screen will sit. Align the new screen with the connectors and press it firmly into place. Ensure it is secure and flush with the frame.

Reconnect the display connector and any other cables to the motherboard. Reattach the rear housing and secure it with the screws removed earlier. Ensure all components are properly aligned and secure.

Gently reinsert the SIM card and microSD card into their respective slots. Make sure they are fully seated and secure.

Place the battery back into its compartment and reattach the back cover. Press down along the edges to ensure the cover is securely snapped into place.