The member list can be updated an any time. Refer to Member Import for details on the source of the import file and the required export settings.
The process of importing a member list for the first time and updating an existing member list is identical. Member already present in the database will be updated by this process. Members who are missing from the database will be added to it.
Once the download of saved, select 'Import Member Records' from the main menu. Navigate to the file already downloaded, and click Open. The process of updating member records is quite fast and causes only minor delay.