I upgraded this evening to 2.0 and am wanting to switch back to 1.5. I backed up my databases and saved all my old files. I deleted the new installation and uploaded all my old files. When I access my website, it tells me: "It doesn't look like you've installed WP yet. Try running install.php."
So I try to run the install and it tells me: "You appear to have already installed WordPress. To reinstall please clear your old database tables first."
I'm not sure how to clear my tables. Do I just delete the DB and re-create and then import my old DB or is there a better way to do this?