Using the Management Center while Replications are Running
When the Replication Agent is running, possible actions in the Management Center are as follows:
You can create and enable new replications (both transactional and refresh.) The Replication Agent is able to add replications to its tasks without first stopping then restarting the replicator.
You can add new source and target connections
You can disable/enable any replication
You can update any disabled replication
You cannot update an enabled replication. To modify an enabled replication, first disable it, then make changes, then re-enable the replication.
Modifying/Adding Replication Settings