This sounds simple enough, and it would be, if all stakeholders were in agreement, but the reality is they rarely are and the all want the world but want someone else to pay for it, so having a transparent and structured approach is very helpful.
At the same time as checking the requirements it is important to establish priorities. Not all requirements will have equal priority and a structured approach to decision-making will be needed. Stakeholders will have their own views on what is important to them, and not all can be completely satisfied.
If this is an area where you would like a bit of help, why not have a look at our FAQ on establishing priorities and a technique that will help.