It is likely to have been built in Layers if you have the original AEFX Project File.
Should be easy as changing the Logo Layer but that depends if there were additional FX added to that Layer.
If you open the project and import your new asset all you need to do is find the layer containing the footage you want to replace. Once you find that footage, locate it in the Project panel and select it there. Observe the size of the image. Make sure that your new image is the same size. If necessary resize it in Photoshop. Now, with the original footage selected in the time line move to the Project panel and select the new footage. You then hold down the Alt/Option key and simply drag the new footage to the timeline and it will replace the original.
Problems arise when the replacement footage is a different size than the original, but other than that, things should work just fine. It may even be helpful to open the original file in Photoshop and drag your new file on top if the original so you can properly adjust the size.
Thanks so much!!!