There are no special arrangements that need to be made when moving from a Free Busy sync to a Calendar sync. It is advised that you do not modify your current Free Busy publication and instead create a new Publication for your Calendar sync.
Stub Objects will change from being disabled to being enabled due to the creation of a mailbox to store Calendar information.
Once all information has been synchronized via the new Calendar publication you can either disable the Free Busy publication or if the Free Busy sync is part of an AD publication edit the publication and uncheck the Free Busy option.
