In Word 2007 and above, select the Mailings tab then click the dropdown arrow on the Insert Merge Field icon.
In Word XP and 2003, ensure the Mail Merge toolbar is switched on by clicking View > Toolbars > Mail Merge. Click the Insert merge field icon, select the Insert option of Database Fields, then select the required field and click Insert.
When inserting a date field like date of birth, right click on the date field and select Toggle Field Codes. Edit the format of the merged field to remove the time component from the date displayed, e.g.{MERGEFIELD “DOB”\@”DD/MM/YYYY”}.
For comprehensive information on the use and formatting of mergefields consult the help available within the Word document.