Beginning Theme caused blank white page. Site is DOWN. Can't access admin to UNDO theme setting.

Downloaded 'beginning' imported and could not see it as a dropdown selection. Checked filed structure, I noticed the double folder "beginning/beginning" so, as an attempt to fix the drop down availability issue, I removed the 2nd folder; logged out then back in. Happily, "Beginning" was now avail w/in the drop down. Once I changed the setting from 'DEFAULT' theme to Beginning, saved and went to view, I got a white/blank page. Exited, re-entered and can see the below ERROR info but can NO LONGER access the Administer area at all! Don't know what to do to access the RESET button or UNDO the Theme selection.... Site is now down. I had not had a chance to build much content, so I'm not worried about starting fresh...I just want my site accessibility back...

"My Account" - (shows the below error info)
"Create Content" - renders a blank
"Administer" - renders a blank
"Log Out" - works and logs out

Pls advs what to do to get access back to my Administer area again to start over...

PLEASE HELP! Thanks!

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* warning: include(./themes/beginning/beginning/page.tpl.php) [function.include]: failed to open stream: No such file or directory in /home/thev5633/public_html/myprayerrequest.info/includes/theme.inc on line 971.
* warning: include(./themes/beginning/beginning/page.tpl.php) [function.include]: failed to open stream: No such file or directory in /home/thev5633/public_html/myprayerrequest.info/includes/theme.inc on line 971.
* warning: include() [function.include]: Failed opening './themes/beginning/beginning/page.tpl.php' for inclusion (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/thev5633/public_html/myprayerrequest.info/includes/theme.inc on line 971.