Migrating a page to be an article

I’ve decided, that some second level pages I have, should really be blog articles. I want to copy and paste the title and body to an article and then delete the page (is there a better way of doing this?).

Now I’m worrying about already existing links to the pages. I don’t want them to break …

can I somehow enter the old URL as an alias URL for the article? Or maybe forward from
http://mypage.com/level-one/level-two-page/
to
http://mypage.com/2010/07/30/level-two-page-as-article/
without showing the olt level-two-page in the navigation?

Use the Vice Versa plugin to change the post type.
Redirect the URL per .htaccess:

Redirect permanent /old-url /new-url