You can do what has been suggested.....

or....

You can do what I would likely do which is, start over in BB. Seriously, it's not going to take you very long to lay out the chords to a song.... slap on a style and record the vocals.... I think this route would be faster, especially if you're not familiar with the details and have to edit the tracks to add blank measures up front.... just saying.

You can find my music at:
www.herbhartley.com
Add nothing that adds nothing to the music.
You can make excuses or you can make progress but not both.

The magic you are looking for is in the work you are avoiding.