If your database name is, for example: OJS
mysql -u root -p
CREATE DATABASE newojs CHARACTER SET utf8;
quit
mysqldump -u root -p --opt --quote-names --skip-set-charset --default-character-set=latin1 OJS > dumplatin1.sql
mysql -u root -p --default-character-set=utf8 newojs < dumplatin1.sql
And you can to edit ‘config.inc.php’
Database settings
database name = newojs
This is for testing. You should create an user for your new db.