If all works well, you may eventually remove the original (old) Connector objects in Configuration - Repository Objects - Connector and the connector JAR file from $midpoint.home/icf-connectors directory. After that you have to restart your application server.
TODO: connector management GUI
MidPoint can do all kind of smart things with resources and connectors. But most of the configuration needs to be done with XML/JSON/YAML files. The user interface support for connector and resource configuration is somehow limited. And this seems to be perfectly acceptable for many midPoint users.
However, there is always a possibility to extend midPoint user interface. Especially some user interface to manage the connectors and assist connector upgrades would be useful. Evolveum offers subscription programs that can be used to fill in missing midPoint functionality.