Data Sorter Needed To Alter Pre-existing Spreadsheet Statistics

I have a spreadsheet with 2700 food items. These items are broken down into categories with Serving sizes and calories. I need a good worker to quickly create different serving sizes for about 2000 of these entries. This will include taking items that are above a certain calorie count and reducing the serving size and calories (up to 2 times) and entering the data into another column... You can easily use a calculator for this. It's simple. But needs to be done quickly. I will send the criteria to qualified workers. (You must have an excellent rating to be hired)