Cannot alter schema name in MYSQL 5.5 w/ MYSQL Workbench

Actually, you can rename database name very easily,

1. go to the top menu -> Database -> reverse engineering, select your database and keep go further until you get the er diagram of your database,
2. after the there is an area called Catalog Area under that you can see your database name, right click on that and select edit schema. and change your database name
3. now again go to the top menu -> database -> forward engineering and completed the database engineering using the wizard.

There is no RENAME available for schema names. You will have to export the schema, then import with a new database name.

This is a limitation of the MySQL server itself.