Design - Change Logos

I need someone who is a Photoshop expert. I have a product which I am selling, which my mother company also sells. I want to remove their logo from the photos and replace it with my own as theirs looks alot better then the photos I had taken and they have given me written permission to do so. All in all there are about 33 pictures, you need to only brand certain pictures and watermark them all with my logo. I need this done asap this is not a difficult task I need it done within a few hours tops. Total budget is $30.00 USD. Will create full milestone will not release any money until completion.