I'm trying to upgrade my DNN installation to 8.0.4 from 7.4.2. I've downloaded the upgrade package from github and unzipped into my website directory as I've done so for many upgrade in the past to 7.4.2. I can confirm that the install.aspx file is indeed inside the /Install folder but for some reason when I navigate to:

mysite.com/Install/Install.aspx?mode=upgrade

I'm getting a Server Error:

The resource cannot be found.Description: HTTP 404. The resource you are looking for (or one of its dependencies) could have been removed, had its name changed, or is temporarily unavailable. Please review the following URL and make sure that it is spelled correctly.

Requested URL: /install/Install.aspx

Not sure what i'm doing wrong? The web.config file does have auto-upgrade set to true.