Rollback from a patch

Is it possible to roll back from an FM12 patch?

For example, if I install 12.0.4 on 12.0.3, then decide I do not like it because it breaks something that I need, can I roll back to 12.0.3?

Or if not roll back, can I accomplish the same goal by installing 12.0.3 on top of 12.0.4?

Got the general idea?

Best,