Repackage opensource application with slight changes

Hello, I have 1 open source application that I need to slightly modify by adding a personal image next to the original logo, the application runs on both MacOs (.pkg) and Windows (.msi), I would like to find someone who can help me modify the installers to in order to make the changes persist since you installed the application. At no time will the proprietary name of the application be removed, nor will its trademark rights be violated, I just need to add a personal image next to the original image in order to customize it just a little.

Please, only people with experience and capable of doing what I request. Thank you