Best method would be to create a new table:

Addressbook_temp

run a script thus:

insert into  Addressbook_temp
select  ID,FirstName,LastName,City,State,Zip  from addressbook
group by  ID,FirstName,LastName,City,State,Zip

delete the old table addressbook and then rename Addressbook_temp to Addressbook

Best method would be not to allow duplicates, via using a replace statement to insert data into your database. But that depends on the database you are using.

Technological progress is like an axe in the hands of a pathological criminal

Remove ID from the group clause else you'll obtain the same table. I believe is an ordinary Access base with ID assigned automatically.
Do not forget to assign a UNIQUE clause to the table for FirstName or FirstName and LastName or whatever field(s) you think it will be necessary, to avoid future record duplication.