?failed? Install = no access. What next?

SITUATION:
I've been upgrading my blog from the defaul theme.
I installed the Atahualpa Theme, but when I went to themes/Atahualpa/configuration options [about 20 rectangular setup boxes] ALL of the individual
choices merely relaunched the same setup menu:
I couldn't actuallly make ANY configuration choices,
so NONE of my sidebar information displays.

Q: Did I make an installation error,
or is that menu itself borked?
HOW DO I FIX IT?

Q: Before I could change back to the default theme,
my browser crashed with Atahualpa installed, BUT NOT
CONFIGURED, so the META section does not display and I can't log in to fix it. HOW DO I GET BACK IN TO RESET THE DEFAULT THEME UNTIL I CAN GET Atahualpa WORKING PROPERLY?

Thanks!


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