1. Play your midi file on any player to get the start and end time of each "song" you want to separate from the hour long midi file.
2. Import the hour long midi file into Audacity
3. Drag select the notes from the start and end time of each song and click "cut". If there were pronounced breaks between each song you will probably be able to see where those breaks are on the editor to make it easier to select the start and end points.
4. Open "new" file and "paste"
5. Export this as your new midi file for each "song"
6. Go to #3 and Repeat for each "song" you want to separate.