[midwest]

use phpmyadmin
select the database of choice

#4
drop all tables
note: do not delete the database, just drop the tables

#5
use the function under the import tab to "file to import"(that is the sql file you untared) If you run into time out problems ftp the sql file to your root and use ssh with the mysql monitor, or you may split the sql file into chunks by CREATE_TABLE sections.

standard disclaimer
YMMV
not responsible if your computer blows up, blah,blah.

HTH