See:
http://allenbrowne.com/func-DAO.html#DAORecordsetExample
To modify the field, use your field and table names in the SQL string, and
replace the line:
Debug.Print rs!MyField
with:
rs.Edit
rs!address = 99
rs.Update
Note that the code loops through all the records and would replace them all.
To modify fewer records, add a WHERE clause to the SQL statement.
You could also do this with an update query, e.g.:
Dim db As DAO.Database
Dim strSql As String
Set db = CurrentDb()
strSql = "UPDATE ACCOUNT SET address = 99 WHERE ID = 767;"
db.Execute strSql, dbFailOnError
Debug.Print db.RecordsAffected & " record(s) updated."
Set db = Nothing