This version contains a number of updated packages for security and feature updates. Importantly, the latest stable version of the cloud-init package is installed, fixing an issue caused by a previous version if a user tried to create and launch a new AMI based on the current image.
To upgrade, you only need to start a new instance. If you have any data you wish to back up, you can put it on an EBS volume and then attach that volume to your new running instance. Mount the volume and copy over any desired files. Users can also utilize Ubuntu’s built in backup feature to create backup files of desired folders on a volume which they can similarly attach to the new instance and use the backup program to restore those files from the volume.