How to change the storage engine type on MySQL?

The following article will tell you how to set the default storage engine, how to explicitly use a specific engine during a CREATE TABLE command, and how to change the storage engine of existing tables:

http://dev.mysql.com/doc/refman/5.1/en/storage-engine-setting.html

To change the storage engine of an existing table:

ALTER TABLE my_table ENGINE = InnoDB;

To set InnoDB as default:

Normally, this is MyISAM, but you can change it by using the --default-storage-engine or --default-table-type server startup option, or by setting the default-storage-engine or default-table-type option in the my.cnf configuration file.

If you use are using the mysql workbench there is a script menu option to change the engine of all tables.

Select Plugins > Utilities > Change storage engine of all all tables.