Use the Windows Control Panel Add or Remove Programs tool to remove the Data Replicator.
When you remove a previous version of Data Replicator, a prompt appears asking whether you want to remove the SQDR service properties and the control tables (definitions of sources, destinations, and subscriptions). Select No in response to the question about removing these if you plan to re-install SQDR and want to preserve the properties and control tables that have been defined.
Note that some pre-requisite packages installed with SQDR (e.g. StarSQL, SQDR_ODBC) will not be uninstalled by uninstalling the Data Replicator; these will need to uninstalled individually.