change as it relates to promoting a quality culture

How do I explain why the cultural change in a government agency is so difficult to accomplish by those within the agency? and how do I Determine the degree to which resistance to change correlates to the degree of acceptance to cultural change?  How do I Recommend methodologies and tools for implementation to promote a culture of change within a governmental agency?

I am writing a draft of 5-7 pages and need guidance. I am writing in APA 7 format.