Best Buy does not replace screen protectors. However, if you have a warranty with Best Buy, you may be able to get a replacement screen protector through the warranty.
If you have a cracked screen protector, you will need to remove it and replace it with a new one. Screen protectors are relatively inexpensive and easy to find, so replacing them is not difficult.
Conclusion: Best Buy does not replace screen protectors. If you have a warranty with Best Buy, you may be able to get a replacement screen protector through the warranty. Otherwise, you will need to remove the old screen protector and replace it with a new one.
