what i used to do was read the info, and help them to reword it to read on their level. in a way that they can give the presentation on their level and in words that they understand and can easily present. maybe you can start by doing an outline of the facts you want to include in the report and then just break it down to 3rd grade level.
seems like we do get to do the projects, but i always felt guilty or like cheating when i helped one that young, makes me wonder who do the teacher think is suppose to do the project.