When I am able to load it I run Ubuntu 12.04 LTS. At this time I have
password disaster as nothing works. Is there any way that is available to
me now to remove all nonfunctional passwords and start from scratch with an
all new password? Or is it possible to simply delete 12.04 and reinstall it
again?

I will sincerely appreciate any helpful advice offering solutions. This
message is sent using Mint.