How do I view instance data

The answer will depend on what you've used in 2003 to view the data for running process instances.

If it was a custom app using K2ROM, you should be able to do the same using the SourceCode.Workflow.Client API.

If it was through reporting, you should still be able to do it through reporting - if not through standard reports, certainly through custom reports.  We are in the process of enhancing/adding to our standard reports and you should soon be able to access all the normal 2003 reports in K2 [blackpearl] as well.

Regards,

Ockert