I had to get my iMac's hard drive fixed a little while back and it turned out I needed a replacement hard drive. No worries, got that done ... BUT the guy who replaced it never told me what the password is! So now whenever there's an update or if I want to add software I get the message asking for PW and I don't have it... and of course I lost the guy's phone number. Is there a way around this? A way to reset the password without knowing it???