Hi,
The size of the currently installed and the new version is almost identical, and maybe even smaller – so this is going to be a server related issue unfortunately. The plugin installer file is around 2.9MB, which is extremely small considering other plugin sizes. I wouls strongly recommend increasing the maximum file size limits of the server to at least 4MB, or even more, as most plugins exceed 8MB as well.
Try the automatic updates instead, for that to work you have to activate your license key first.
If you want, you can add temporary FTP and back-end details, and I will take a closer look at the error messages, and try to install the plugin for you.