My sister inherited an iPhone 4 from a friend... but any attempt to use the camera would hang the phone. Being the geeky big brother, I naturally offered to fix it!
Someone had obviously been into the phone ahead of me, because the main entry screws weren't the stock items. Got inside easily, following the iFixit how to guide... swapped the new rear camera module in, and it worked like a charm!
Don't be afraid of taking on a repair for a family member! They will love you even more because you've fixed it!