Existing users of VisiBroker 8.5 who wish to upgrade to Service Pack 6 should follow the instructions in the VisiBroker 8.5.5 Release Notes to install the Service Pack on top of their existing installation.Existing VisiBroker users upgrading from previous versions can switch between security providers by using the SelectSecurityProvider utility which was delivered as part of SP2. For details of how to do this, see the section Specifying the Security Provider in the VisiBroker Security Guide.