Aggressive sales people can be difficult to deal with and many people find it hard to work effectively with them. Realizing that it is the behavior that's causing this along with negotiations skills can help you not take things personally and deal more effectively with them.
Follow these steps to help you deal effectively with an aggressive sales person.
1. Identify what is actually happening. What is the situation, behavior or action contributing to the difficulty? What pressures are they under? Does everyone else have the same issues? Is it you/your company that are unwittingly contributing to the problem? Disassociate the behavior from the person as much as you can. This will allow you not to take it personally and deal with it objectively which in turn can help take away any negotiations skills that you have.
If the person is being unreasonable after assessing the above, are there other people within the organization who have the decision-making ability? Alternatively are you friendly with anyone who can help you deal with this person - look at your resources and use negotiations skills.
2. Stop wishing that the person would be different. Accept them for what they are and that they are showing aggression for whatever reason and move on (this depends on the severity of the aggression). This doesn't mean you cannot influence a change in their negotiations skills but there is little point in wasting time trying at this stage.
3. Look at it objectively. Am I this way to anyone? Can you identify with it - If so, how best would it be to tackle you in this situation. Have you used negotiations skills in the past that could be used here? Use this time to identify what you want to happen here.
4. Plan your strategy. Have the end result in mind. Take time to think each step through and try and anticipate all possible outcomes. What is it you want to achieve? Always have this in mind and work your negotiations skills backwards to create the strategy to achieve this.
5. Put your plan into action. What do you need to have in place to achieve it? This is not about win at all costs; you may need to 'give in' on certain negotiations skills to get what you want.
6. Assess how it went and learn from it. What worked well? What could have worked better?
Often aggressive people give more away than passive and you can gain vital negotiations skills from them that can help give YOU the vital balance of power.