Separate the person from the problem you are trying to influence. Most people want to solve the problem so they go hard at the person. This is a huge mistake! By going hard at the person they get offended, resentful or rebellious. It is no way to influence.
The idea here is to go warm with the person (not insincere or manipulative) just appreciate them, their effort, their integrity, their passion. Acknowledge that you want to kick around the problem or idea, not them and their feelings.
By being warm with the individual and explicitly stating that it is neither personal nor disrespecting their right to take a position. Then you can agree to go hard at the problem. You want to work it out together, but that doesn’t mean consensus, be clear about that.
Ultimately you want the other person walking away from you saying, “We had a robust conversation, we worked out the problem, and I respect them more from the interaction”. Not the opposite.
Focus on underlying interests – not positions.
Too often people get into conflict, often over email, because of their position vs the other’s position. It leads to clashes, bargaining and escalating and all kinds of the worst form of human behaviour.
Focusing on the underlying interests, means understanding why they might hold a particular view. By understanding how their interests and your interests can be met then you can be more creative and collaborative about a solution. This is not fluffy, it is focusing on what really matters to that person.
It requires reading between the lines, acknowledging what is being said, but also what is not being said, and deepening your interpretation to see the wider field. Once their interests are met, they are far more likely to work with you to get yours met.
Generate many options before deciding which will work.
We switch on our creativity to solve a problem right up until we come up with a solution. Then we generally switch off our creativity and simply look for evidence why it is the best and only way to go. This is one-dimensional.
We need to keep our creativity switched on, when we got one solution, look for another, and another, and another; taking into account the different challenges and directions the discussion may take.
By having multiple options to use we can be much more flexible about influencing the other side. It just requires us to have a bit more thinking time, and more than one solution.