The iPod Touch contains two screens: the outer glass protective screen, and the actual touch screen (also called the digitiser). The steps below explain how to replace both, depending on which is broken.
Replacing the LCD Digitizer – Carefully remove the chrome backing of your iPod with your iPod opening tools (or a Flathead screwdriver). Do this by sliding the tool between the gap of the chrome backing and the front faceplate. After working your way steadily around the iPod, the back will pop off.
Place your iPod face down on a table or other surface. You now need to remove the rechargeable battery.Do so by carefully prying it upward. It is glued to the iPod so it’ll take some effort to remove it.
Take out the liquid crystal display (LCD) digitizer. The digitizer is held in place by 16 tiny screws. Keep the screws in a safe place.If applicable, replace the broken digitizer with a new one. Do this by unplugging your broken LCD screen carefully (you can see the black plug in the image), then plug in your new LCD screen.
Put your iPod back together by reversing these steps. If you are replacing your outer protective screen proceed to the next step.
Lay the faceplate face up and heat with a hairdryer. The adhesive holding the screen to the faceplate needs to be heated to separate the two. Remove and discard the cracked screen.
Now replace your ‘home’ button and lay your replacement screen over your faceplate.Heat the faceplate with your hairdryer to allow the adhesive to bond with the screen.