I've actually done this a while ago. I've enabled HTTPS on the site. I also updated the forums to 2.0.14, which helped to make things work - most notably images from HTTP sources. Browsers shouldn't complain now that HTTP sourced images are being converted to HTTPS via a proxy.
Now for the broken stuff. Apparently the update changed how SQL queries are handled, so some of the mods are broken. It seems it's just Pets, Arcade, and Inferno. I'll be working on fixing those over the weekend.