Exactly how do I get free credit reports from the 3 major credit reporting companies?

sylvia1943 asked:

I’m trying to help my step-daughter get the free credit reports which the 3 major credit reporting companies are suppose to provide. She can not find a phone number for any of the companies which is answered by a human. What must she do?
Write them? If it can be done through the Internet, exactly which are the real websites?. Any and all help or suggestions are greatly appreciated.
Thank you