Select the sheet you want to edit. To select several adjacent sheets, select the first sheet, hold "Shift" and click the last sheet. Select several nonadjacent sheets by holding "Ctrl" and clicking each sheet. To select all sheets in the workbook, right-click one of them and click "Select All Sheets."
Select the "Page Layout" tab and then click "Margins" in the Page Setup group. Select one of the predefined margin sizes -- Normal, Wide or Narrow -- or click "Custom Margins" to use custom margins. Change the "Top," "Right," "Bottom" and "Left" margin sizes. To change the size of the header or footer, change the "Header" or "Footer" values. Check the "Horizontally" box to center the sheet horizontally on the page, or the "Vertically" box to center the sheet vertically. Click the "Print Preview" button to preview the document or the "Print" button to print the sheet.