For Avante you can download either of the Avante 10.3.1 packages. The one that you have on your screenshot is the ISO which is just packaged as a "DVD" that can be mounted or burned to disc. The other one by the same name but without the "ISO" is a self-extracting file that will unpack the installer files to a folder of your choice and then you can run the setup from the root of the unpacked folder. The setup launches a menu where you can choose which component to install. From 9.2.1 I believe it'll do a direct upgrade "in-place" to 10.3.1 but, especially since it's a large jump of versions be sure you have a good backup of the server before you begin.

Install the Server first, then Client (on the server itself so you have Admin console), then Workflow, then Weblink. (Weblink is called Public Portal now and has its own download on the support site. It's also not matched to the 10.3.1 version so don't let that throw you)