Note: I'M NOT BIDDING ON YOUR PROJECT. However, I'll give you some free tips. It depends what email service you use. If you use gmail or yahoo or something, the attachment exists on a server somewhere and you'll never be able to change the attachment itself because you'll never get access to it. However, what you CAN do... If the email is downloaded on your computer, disconnect from the internet. The attachment was downloaded somewhere to your file system, most likely in the "Program Files" of whatever program you use to read email (for example, Microsoft Outlook). Although this is technical, you could have your selected freelancer explain how to do it for you if you aren't technically inclined. I am just letting you know that if some freelancer says this is completely possible, they are lying to you. It is impossible to change the attachment without hacking into Gmail or Yahoo or whatever email service you use (completely impossible). It is only possible to make it LOOK like the attachment is something different on whatever local computer you download it on. Good luck to you.