Migrating a MySQL database to YugabyteDB can be done using the pgloader tool, which provides a PostgreSQL-compatible distributed SQL database. To start the migration process, prerequisites such as accessing the MySQL database and having ysqlsh command line connectivity to a running YugabyteDB cluster are needed. A separate machine is recommended for installing and running pgloader to avoid stealing resources from the target or source servers. The pgloader instance needs to be able to connect to both the MySQL source database and the YugabyteDB target cluster, with necessary permissions granted. Once the setup is complete, a command file can be used to simplify the docker command, and the pgloader can be run to migrate the schema and data from MySQL to YugabyteDB. The migration process can also be done for just the schema, and validation steps include checking the platform UI for the presence of tables and active queries.