We've added https

We moved servers to our university and now have the site as an https:.

A few questions
Is there a way to automatically update all code to refer to the https configuration. I noticed on the created sites they still show as http: although they default to https when clicked through. The greater challenge is the system wide update - I get an error message that each site can't be accessed and it seems this is the issue.

Any other changes we need to make that others have run into? I've posted a question about 301 redirects with WPMU SEO plugin and I have a suspicion it is related to this.

As always, I appreciate any and all input.