This tool will attempt to migrate an old Matrix account to a new (already created) account. The new account may optionally be on a different, federated server.
Migration is performed by logging in on behalf of your old and new accounts and automatically inviting your new account in to all of the rooms that your old account is in. You can optionally request that your old user leaves rooms once the new user has successfully joined. Account metadata such as display name and avatar can also be migrated.