How to Merge and Center Headers in Microsoft Excel 2007

1.
Select the cells you would like centered above the table in the worksheet.
2.
Click on the 'Merge and Center' icon located in the Home Tab on the Ribbon. The Ribbon is the group of icons and tools located directly above the work area.
3.
Click on the 'Merge and Center' option from the drop-down menu.
4. Click on the 'Unmerge Cells' option to un-merge the cells.