Long BookIDs

[rcatala]

I have recently consolidated the various folders on my laptop that had a mix of KMA and KMH files into one folder. I then erased the songs database so that on my next restart, the new song database would be created. Everything worked fine, but somewhere along the line, I have ended up with BookIDs that are 9 digits long. This makes it mistake-prone when someone looks at the songbook and has to write down a 9 digit number (7 digit root and 2 digit track).
Is there a way to renumber the BookIDs? I don't mind having to print new songbooks.
Thanks