Is it possible to download an old version?

I need to upgrade an old version of the theme so that it works with WordPress 4.0. Unfortunately the people who created the site modified the theme files directly (instead of creating a child theme), and I do not know exactly which files they changed.

If I could get a copy of version 2.4.5 then I could simple diff the files and see what they modified. Otherwise it will be a tedious process of trial and error.

Thanks for your help!