Forgotten username and password - how complicated is this?

Sorry, a newbie here, but I simply cannot understand the instructions when trying to reset the password. I’ve only just bought and installed Green, and don’t care if nothing is saved, I just want to get back in. Is a complete reinstall possible or an easy reset?

Yes, those were the instructions I meant. All this for a forgotten password??

Yes, it’s all in the guide (even with videos)