How to purchase screen protectors and get help with installing at the Apple Store?

If you can get to an Apple Store or an Authorised Apple Dealer, you can buy a screen protector and have it fitted. Alternatively, in my experience, most phone stores that sell protectors will be happy to install one for you, but there may be an additional charge for installation. You can install a screen protector yourself but, if you go down this route, get one that includes some form of jig or device to ensure that the protector is properly aligned. It's not as difficult as it might appear, just make sure that your phone's screen is absolutely clean before you start. A kit from a reputable supplier will contain all the wipes and alignment frames required. Some even include a second 'spare’ protector. If you are in any doubt, the Apple Store is your best bet.