Need upgrade help - been sooooo long!

Hi all,

Please forgive my lack of expertise. I'm in need of detailed, hopefully simple, instructions. I created a VM probably about 10 years ago and have been running Ubuntu 10.04 guest in a Vista64 host ever since. I know, I know....

I'll be upgrading my whole system soon, but for now, Ubuntu is on its last legs and it's such an old version I can't even upgrade it in stages, so I just want to do a clean install of the latest and greatest. But how?

Please assume I don't even know step 1 of this process (since I probably don't) and try to be as "VMs-For-Dummies" as possible.

Thank you!

-Frank