First, I'm not sure what you mean about 'think like small business owners'. I know what I mean but your defintion may include behaviors that I don't see. What exactly are the behaviors that you seek to shift? Without a clear vision of what that actually means it becomes generic language that is difficult to systematically implement.
Having someone come in and faciliate the mindshift desired (once articulated) will go a long way to making it happen since it will not appear like this is your directive that other executives have to follow, it's a company wide revisioning and repurposing of efforts and behavior. What has to be uncovered and resolved are things like: What are the executives still attached to from the former structure? is it a sense of power/influence, is it a sense of importance, etc. and What are their feelings about the downshift? Do they feel like they have gone from being a luxury cruiseliner to a dinghy? Getting all that stuff up and out on the table will help. Without that, you have only the imagining of what's going on inside them that is generating the seemingness of resistance. When something is going on with someone and you're not sure how to handle what's going on with them. Ask. Get to the source, and then you have something you can deal with.