Take, for example, the famous boiled frog story. Put a frog in a pot of hot water and he will jump out at once. Put him in a pan of cold water, heat it on the stove, and he will be cooked to death because he won't notice the slowly rising temperature. Moral? Let frogs (and people) get used to new things slowly; don't try to change everything all at once.
Here's another frog story. A scorpion and a frog meet on a riverbank. The scorpion, who can't swim, asks the frog for a ride. The frog demurs; "Why would I do that? You'll sting me and I'll die." Says the scorpion, "That would be stupid. I would die too." OK, says the frog and they start across. They get partway and the scorpion stings the frog, who with his dying breath, says, "Why did you do that? Now we'll both die." The scorpion shrugs; "I'm a scorpion." Moral? Don't trust scorpions (and people) to go against their instincts.
Both of these are powerful images, and the advice they embody is worth noting. But maybe not all the time. First of all, the boiled frog story is surely untrue, simply something made up for the purpose of illustrating a point. I have not done the experiment, but I am morally certain that the frog, any live frog, would jump out of the pot long before it boiled to death. So, another moral to this story is; "Don't assume frogs (or people) will necessarily either resist sudden large changes or accept continuing small ones.
A similar point applies to the scorpion story. Even though scorpions (and people) have a set of inherent tendencies or routines that are easily triggered, that does not necessarily happen in every case. I am not an expert on scorpions, but I know without question that people can be encouraged and led to act against what appears to be their nature, or their inclination. The real danger is actually the assumption that their behavior is always predictable and unchangeable: "If I do this, they will certainly do that."
The best way of getting people to accept change is not to try to fool them, or to make rigid assumptions about them, but to get their support, based on their own understanding and your willingness to work with them.