Joomla! 1.7 introduces a Quick Update for sites already Update with Joomla 1.6.5 or 1.6.6 is fairly easy.
To Update Joomla 1.6.5 or Joomla 1.6.6 to Joomla 1.7, do the following:
– Backup your website
– In the top menu, locate the link Extensions. Click Extensions from the drop down menu that appears click Extensions Manager as shown in Image 1.
– Click Update as shown in Image 2
– After click Find Updates, the screen as shown in Image 4.
– Click the checkbox to the left of the Joomla line containing the latest Version Number, then click Update as shown in Image 5.
– When the update has finished, you will be presented with this page.