By "transfer my music library", do you mean moving your actual music files, or moving your MusicBee library (MusicBeeLibrary.mbl and related settings/index files)? Are you keeping your MusicBee application installation in the same place?
If all you're doing is moving the music files referenced in your MusicBee library to a different drive or folder, File-->Library-->Relink Music File Paths should do what you want.