Different Frame-Rates

Hey guys... I've encountered a slight problem while looking through the footage for a project I just shot.
On Saturday, I shot a chunk of footage with my T3i at 23.98 fps. This was my desired framerate for the project. However, the subsequent footage I shot was accidentally captured at 29.97 fps. I have no idea how that happened, as I definitely didn't go in and change the framerates myself. All I can think of is that I accidentally toggled some sort of "reset" and didn't even realize it.
When I edit this, I want to keep the 23.98 framerate, if possible. Is there a way to "down-convert" the 29.97 fps footage to 23.98 and have it look good?