The power and volume buttons on your LG K7 allow you to turn it on/off and adjust the volume. If they stop working, wear is usually the cause; however, you can replace them within 25 minutes using these steps:
Remove the back cover with a plastic opening tool.
Be careful not to damage the frame as it is made of thin plastic.
Use a plastic opening tool to pry off the silver button housing.
Remove the plastic opening tool from the package.
Do not bend the outer frame or screen when separating them, as this can severely damage the phone.
Use a plastic opening tool to carefully peel off the orange cable.
Use a plastic opening tool to carefully pry the volume/power button cable away from the rest of the phone, breaking the adhesive.
Enter your pincode to see if Cash on Delivery is available in your area.