Well, to start with be visible and go out and about to find out what is really happening, "walk the floor".
You can also set up one to one with employees or group talks to discuss and explain what kind of culture / behaviour is and is not acceptable in your company and set expectations that are understood by all (try to explain what does this mean in practice, concepts could mean different things to different people).
In regards to change, what people fear is uncertainty and what this will mean to them. Be clear, open and transparent as far as it reasonable practicable, and elaborate how change will affect them.
If there are no implications for their job (e.g. no job losses or reductions of hours/premiums) than say so and remove this barrier.