R600/ R500 FIRMWARE UPGRADE Unleashed without internet connection

[nohands]

I have just taken over a site with R600/R500's running unleashed. The site uses a proxy and some severe firewalls that prevent direct access to the internet. The APs are running 200.0.9.9.608 and the administer>upgrade only gives one button to upgrade which fails. The Dashboard seems to think it has internet access but this is not the case. How do I get the option to manually update the APs?