Hold the power button and select 'Power Off' to turn off your Motorola Moto Edge 40. Wait a few seconds to ensure the device is completely powered down before proceeding.

Using a SIM eject tool or a paperclip, carefully remove the SIM card tray from the device. Set the tray and SIM card aside in a safe place.

Using a heat gun or hairdryer, gently heat the edges of the back cover to soften the adhesive. Be careful not to overheat the device. This should take about 2-3 minutes.

Use a suction cup to lift a corner of the back cover. Insert a plastic opening tool into the gap and carefully work your way around the edges to release the adhesive. Avoid using metal tools to prevent scratches.

Locate the battery connector and use a spudger to gently pry it off the motherboard. This will ensure that no power is flowing to the device during the repair.

Unscrew the screws securing the display connector shield using a Phillips #00 screwdriver. Carefully disconnect the display cable using a spudger, then use a heat gun to warm the edges of the display and loosen the adhesive. Gently lift and remove the display assembly using a suction cup and plastic opening tool.

Align the new screen with the device frame. Connect the display cable to the motherboard and secure it with the screws you previously removed. Ensure the screen is correctly seated and all connections are secure.

Reconnect the battery connector to the motherboard. Carefully align and press the back cover onto the device, ensuring the adhesive bonds properly. Reinsert the SIM card tray.

Power on your device to ensure the new screen functions correctly. Check for touch responsiveness and display quality.