Problem description:
In our project we have one \"production database\" and many \"devs\". We want to know how we can manage and install the changes. We already have
You describe a process that's being used in lots of dev shops, I'm pretty sure - including in my company, too.
If you want to stick with this, one tool that's helped us is SSW SQL Deploy which allows you to grab a whole bunch of scripts (we have a "changes" folder for each version, and the files are label "001_something.sql" through "999_somethingelse.sql") and execute those as a whole against a database. You can also include that into your .NET apps via an API, or you can launch it from the command line during an install.
The highest end of the spectrum is to adopt a whole database change management process, something like DB Ghost by Innovartis, which is a lot more than just a bunch of tools. But this would require you and your devs to adopt that style thoroughly and live and breathe it. Very interesting, but so far, I haven't managed to convince my devs and bosses :-( Maybe you have more luck?