If you have Scribe and are handy with T-SQL, piece of cake. Just join across the databases to build a source dataset.
Without Scribe, it's still fairly easy to import Contacts using the Import Data templates by pasting your data from SQL (restore the backup to a temporary database) to Excel. It could be much more difficult to fully recover the Appointments however.
I'd suggest you take a look at a
post from Leon Tribe that describes importing Appointments.
If time is of the essence, you may want to find someone experienced to help.