Remove mywebsite.com/author/admin/ page

Googling myself (don’t we all do that?) I found a page to my website showing up quite high in the results at mywebsite.com/author/admin/ page. I do not want that to be up at all, since it doesn’t look good and is useless. How can I remove this page completely or make it a 404 or send any vistitors to the main page? Telling Google not to go there is maybe a possibilty, but on the other hand I should be able to remove unwanted pages. There is one plugin saying it can do that, but it looks abandoned.