Export Contacts from the Mozilla Thunderbird or Netscape Address Book
To export your Mozilla Thunderbird, Mozilla or Netscape Address Book:
Select Window | Address Book from the menu.
Highlight the desired address book in the Address Books list.
If you are not sure which to select, choose Personal Address Book.
Select Tools | Export... from the menu.
Make sure Comma Separated (*.csv) is set under Format:.
Choose a location (your Desktop, for example) and file name.