Currently this is fiddly to do with Deployment Manager. You'll need to download the NuGet database package, unzip it, then use a copy of SQL Compare to compare the db\\state\\ folder with your target database.
We're currently working on a much simpler way to do this automatically. If you have a few moments it would be great to talk through you needs and what we're working on to see if it's a match?
My email is email@example.com
- if you drop me an email we can arrange a time