Step 1: Click on the magnifying glass in the lower left corner and search for Software Center.
Step 2: In the left pane, select Operating Systems, then select the operating system you want to install.
Step 3: Click Install. [Note: You must have at least 26GB free space for this installation]
Step 4: The update process will take approximately 40 minutes. You can continue to use the computer during this time.
Step 5: After the update, you may be prompted to restart your computer.
Step 6: After restarting, the operating system update will be completed.