I'm assuming you want some followup revisions, not just a one-shot revision. It looks like the script is a small piece of a larger system - it would help to have a sense of how the script fits in to the system. It also looks like the script has multiple reviewers, who will have feedback for any revision, so it won't be done until all reviewers are satisfied. My bid assumes there will be several rounds of revision to accomplish that, which will take some time.