Hello, I am a Photo and Media Editor based in Munich and would like to help u in this project. I would have to see the file to be able to say if it´s possible to remove the logo/watermark. If the file is "flat", no layers, no adobe premiere or final cut or even imovie, the chances are very low. If it´s a .mov or similar file the solution would be cropping the video (if the logo is on the corner), or creating another logo and place it. But as said, I would have to check the file first.
Best regards,
Tatiana