By the way Jack, if you have saved your settings either to floppy or SD card, you can then call up your recording,press 'Play' and turn your Tempo Wheel to either faster or slower. You will be able to hear the changed tempo as you work. When you are satisfied, save it again either under another name or by overwriting the original recording. Personally I would save the new slower/faster song under another name.
The beauty of doing it this way is you can listen to your changes before saving.