You can obtain the software required to update the Alcatel One Touch 3040 from the official website. Besides software you also have the possibility to download manuals. I recommend you to download and read the available manuals before starting any operation related to firmware upgrade. On you are done, download the One Touch Upgrade application and install it. After you've installed, connect the phone and follow the instructions.
I also recommend to use the PC Suite application on the same page to perform a full backup of your phone n case something goes wrong.