In one sense it's easy to move to an agile way of doing things. You send your people on some training, start using sprints, change your Product Managers to Product Owners, maybe hire a consultant to spend some time advising your staff, and you're agile, right?
There are 2 big issues with that description:
1. You can't force long-term behavioural change;
2. There is no "agile way of doing things".
And yet that description of how companies change to agile is accurate in a large number of organisations. Sure, the details may be slightly different and there are differing levels of commitment and intent, but in general the notion of changing procedures to "do things in an agile way" is a very common way of moving from [whatever went before] to "agile". The key error in this situation is that what needs to be changed is not behaviours as such, but attitudes.
It's true that behaviours do need to change when you move to an agile methodology, because, for example in the case of Scrum, you've got new roles of Product Owner and Scrum Master, new ceremonies for planning, review, retrospective, grooming and daily scrums, and new artefacts to interact with like a backlog and user stories. The daily and weekly routines that people are used to will change, as will the release cadence, and different behaviours are needed to deal with these. But these behaviours cannot be forced onto people as an act of managerial diktat.
Everyone involved in an agile transformation must understand that the paradigm you used to work in is not the paradigm you'll be working in from now on. The biggest intellectual challenge when moving to a new paradigm is not a new way of doing things, it's a new way of thinking. Moving to an agile methodology is exactly the kind of paradigm shift that requires a new way of thinking, and make no mistake: it's hard.
The classic example of a paradigm shift is the the switch from the Ptolemaic (Earth-centric) model of the planets to the heliocentric (Sun-central) model, also known as the Copernican Revolution. Without wishing to stretch a point too much (because the move from [whatever you were doing before] to an agile methodology is not on the same level as a true paradigm shift like the Copernican Revolution) one of the key problems with a paradigm shift is that you can't compare things between 2 paradigms because they are incommensurable, that is "not-comparable". Now, there is significant debate on how much this incommensurability is true, but in at least some senses you can't compare the claims of one paradigm with those of another because assumptions and boundaries are used to make judgements within a paradigm, and the assumptions and boundaries of 2 paradigms can be radically different.
Therefore it's not the case that you can simply map agile things on to what you did before. The new roles are not "more management". The new ceremonies are not "more meetings". The new artefacts are not "more bureaucracy". They are not these things because in an agile methodology the roles, ceremonies and artefacts are there for the very purpose of removing unnecessary management, meetings and bureaucracy. You use these roles, ceremonies and artefacts to keep management, meetings and bureaucracy to the bare minimum needed to make the vital decisions - prioritisation, estimation, commitment - and convey the vital information between the team members, and between the team and the business.
Telling people to engage in these behaviours - to "do things in an agile way" - will only lead to a begrudging change of process, not a change to an agile paradigm. To achieve that paradigm shift you need to change people's attitudes, because behaviours only become routine and accepted if they flow naturally from an attitude. Think of agile not as a series of actions, but as a field in which those actions take place. Place an object of mass in a gravitational field, and it will act in accordance with the laws that govern that field. This is an analogy that can't be stretched too far for all sorts of reasons, but the general point holds: People act in accordance with the (cultural) field in which they find themselves, which has the practical effect of instilling an attitude in them. They will continue to act in that way until they are placed in another (cultural) field that forces them to modify their attitude.
There is a plethora of information available about how people's behaviours are influenced by the cultural and social attitudes in which they find themselves, so we won't cover any of that here. But trust me when I say that a person's behaviour is determined far more by the behaviour of the people around them, especially people in a position of influence or power, than a lot of those people would like to admit. This means that the most effective way for an organisation to successfully transition to an agile methodology is for leaders and influential people to display the attitudes that will cause others to follow them. It is a top-down process, but through example, not through mandate. If you consider the nature of virtue, it's easy to perform virtuous acts but difficult to be virtuous. Anyone can perform a virtuous act, such as giving to charity, but that is not the same thing as being virtuous. It is the same with agile. Anyone can perform an agile action, such as holding a sprint retrospective, but that is not the same thing as being agile.
It's not about an "agile way of doing things", it's about an agile way of seeing what's in front of you and acting accordingly.