uninstalling wordpress

Hello Everyone – I am attempting to uninstall wordpress to install a clean copy. I started to create a webpage, but decided to go with another theme, and they have suggested that I install a clean copy of WP. So I followed some instructions here and have installed a plugin called WP Data Access to do this. Now, I have it installed, but when I try to run the plugin to clean stuff, I click the uninstall tab and select “reset uninstall settings to defaults” and check the “delete plugin” box. But there is no “go” button. It looks like it didn’t do anything. I’m saying this because when I open my site/dashboard, some of the plugins that I loaded (from my first site building attempt) are still listed in the dashboard. So could anyone explain what I should be doing to remove the original wordpress that I installed ? Is it some kind of cache issue ? Am I doing this properly ? Should I just manually deactivate whatever plugins I originally loaded ? Or do they matter ? thanks in advance – Terry