Comparing Spreadsheets against master (4)

I need someone to compare multiple (6) spreadsheets each with 500, one with 100 contacts against a master list. I need you to be able to see if they are on the master and if so remove them from the individual sheets. The whole point is so there are not duplicates on the master sheet from the individuals. It does not matter if there are two of the same on one of the sheets. Any questions please ask The budget is no more then £100 as it should only take someone who knows excel a couple of hours