Before you do so, move to the "CCCalAppts" layout in the FM7/8 Calendar: this is one of the last layouts, in a section called "Import from Older Versions." (To get thete, run the Show Status Area script and enter layout, then scroll through the layouts until you arrive at your destination.) Once there, you can begin importing your older appointments by lining up the fields like this:

If you don't have any repeating events, you can exclude the PrimeIDX field from the import and leave "Perform Auto Entry..." on. If you DO have repeating events, import just like it is shown above, leave auto entry off and then reset your serial number in the CCCalAppts file when you're done.
Hope that helps.