There are many ways to reduce property taxes and they are explained at Property Tax Appeal, and the first step is to find comparable properties. Also, and equally important is to find what the sales ratio is so one can apply the math to make sense out of the assessment number.
A property assessment is not equal to market value. The market value the assessor feels your property is worth is equal to the assessment value divided by the sales ratio. Most people fail to understand this smoke and mirror trick. They assume a low assessment number means that the tax assessor thinks their property is worth less than the market value and are OK with that. But the truth may be just the opposite!