I just wanna share how I easily upgraded a magento website from version 22.214.171.124 to 126.96.36.199.
Before you do the upgrade, make sure to create a backup file of your magento website, including the files and database.
Tip: The database file will surely be very big, which will take much time if you download it to your desktop. I suggest that you just create a copy of the current database on the server. To do so, go to phymyadmin, then click on the magento database. Click on Operations. Look for the Copy database field to and enter a name for your backup database. Refer on the image below:
Check the website and make sure that everything looks fine.