So if you are using Ebean's DataSourcePool as the DataSource implementation (sounds like you are) then...
DataSourcePool.reset() will remove and close completely all the 'free' connections in the pool. If you have no busy connections that will effectively remove all connections from the pool.
You can possibly also make use of createUnpooledConnection().
If you start using the pool after it was reset() ... then it will create new connections for the pool etc automatically.
By "couldn't renew the connection under the same name." ... I think you probably meant couldn't renew the 'Connection Pool'? ... but I think reset() is probably more what you need.