Guidance on modifying class definitions and switching my application to the new definitions

Hello,

I have a property which I need to move from one class definition to another as follows:

Old definition:

Class SCHED.SchedEntry
{
  
  Property Experiment as %String;

  Property ScanSlot as list of TracerEntry;

}

Class SCHED.TracerEntry
{
  
  Property Tracer As %String

}

I want to move the Experiment property to the TracerEntry class so that there is a different Experiment allowed for each ScanSlot, like this:

Class SCHED.SchedEntry 
{

  Property ScanSlot as list of TracerEntry;

}

Class SCHED.TracerEntry 
{

  Property Tracer As %String;

  Property Experiment As %String;

}

We already have an application running on our production system using the old class definitions, which contains a lot of data.

What are the best practices for updating the development system with the new definitions and migrating the data?  It seems to me that if I compile the new classes, I will no longer be able to access the Experiment property in the SchedEntry class.