How to scrub delinquent tax rolls

[Brandon Osmon]

So we are looking for distressed properties via delinquent tax rolls.  I have received a number of excel files and csv files from various counties but being totally new to this have no idea of how to locate what we are looking for (properties under $80k assessed value with back taxes).  So basically we can gather the information but get stuck at this step.  Any guidance/suggestions on how we scrub these lists efficiently?

Thanks!