Best practices for migrating a development database to a release database

I have searched the Internet... but haven't found much relating to this.

I am wondering on what the best practices are for migrating a
developmemnt database to a release database.  Here is the simplest
example of my situation (real world would be more complex).

Say you have two versions of your application.  A release version and a
development version.  After a month of developing you are ready to
release a new version.  There have been many changes to the development
database that are not in the release database.  However, the release
database contains all your real information (customers, etc...).  What
is the best practice for migrating the development database to the
release database?

I have thought of the following situations:
-Simply track all the changes you made to the development database and
make the same changes to the release database
-Back up the release database... overwrite it with the development
database... then copy all your real data back into the release database
(this last step is probably quite difficult)
-Perhaps some combination of the two


Does anybody have any recommendations?

Regards,
Collin Peters