How to change columns to rows and vice versa

Do the following:

   1.   Highlight the data that you want to change in your spreadsheet:

• the column that you want to change to a row
• the row that you want to change to a column
• the data range in which you want to change columns and rows.

   2.   To copy selected information in the clipboard, do one of the following:

• On the Home tab, in the Clipboard group, click the Copy button:
  
• Right-click in the selection and choose Copy in the popup menu
• Click Ctrl+C.

   3.   Select the cell where you want to place the changed information.

   4.   To paste changed information, do one of the following:

   4.1.   New features in Excel 2016 (like in Excel 2010):

• On the Home tab, in the Clipboard group, select the Paste list and then choose Transpose (T):
  
• Right-click and choose Transpose (T) in the popup menu:
  

   4.2.   Usual way:

• On the Home tab, in the Clipboard group, select the Paste list and then choose Paste Special (or right-click and choose Paste Special... in the popup menu):
  
• In the Paste Special dialog box, check the Transpose checkbox and then click OK:
  

See also this tip in French: Comment changer les colonnes en rangées et vice versa.