How do I move bookmarks from an old profile to a new profile?

I have created a new profile for Firefox and have a huge amount of bookmarks in my old profile. How can I move the bookmarks from my old profile to the new one? I have tried backing up my old bookmarks and then restoring them on the new profile's bookmark library, but this didn't work (the file wouldn't show up and when I put it in a folder to force it to show up it wouldn't do anything). So how can I do this?