How to upload a saved backup of DB and files?

before I added a plugin that I know was the culprit…The Flash Based tag cloud plugin! What i don’t know how to do it to reinstall the most current database…I have a copy of all files for the theme…I can’t figure out why it won’t right itself since I got rid of the plugin, deleted and reinstalled the original php files associated with the front page..fyi all other pages load perfectly if you click on them in the top nav.
So i was thinking of doing a minor reinstall and juts tweaking the php files again. This is a magazine and i needed to add major content tonight that is time sensitive and then this happened.
So, How do i do a db re-upload?