Crop Illustrations in Adobe Illustrator CS3

I require 11 illustrations to be changed in Adobe Illustrator CS3. Each illustration is composed of various objects some of which currently overlay (please see attached pdf file - I could not upload the illustrator file due to the 1024kb restriction). Your task is to crop same coloured object areas so that they don't overlay with any other objects anymore. In other words, if any individual object is deleted the initial drawing board is revealed rather than any other underlaying object. Object with the same colour also need to be grouped together. You have about 1 week time to finish the task. Attention to detail is an absolute must. If I like your bid, you must be willing to submit at least half of the changed drawings before I escrow money. Please attach in your PMB previous work you have done, otherwise I cannot consider your bid.