Best way - one which works for you.
Easiest way - one that doesn't currently exist.
We use a semi-manual method (scripts under source control, small subset of people able to deploy stored procedures to the production server, changes to the schema should be reflected in changes to the underlying checked in files).
What we should do is implement some sort of source control vs plaintext schema dump diff ... but it generally 'works for us' although it's a really faff most of the time.
