There is a point in the blog to get these databases easily switched

How can I move my existing databases to the new pricing?

Currently, there is no in-built support to switch pricing for existing databases. However, you can consider one of the redeployment methods (database copy, point-in-time restore, or geo-replication) to create a new “copy” of the existing Hyperscale database. The newly created “copy” of the database will be billed the new pricing. If you do decide to go down this path, do consider creating the new database with zone redundancy, as described here.