Вот этим
http://www.codevisions.de/news/index.html
MP3 Splitter allows you to split MP3-files either by size or by time. Even very big files can be split. If you wish, it create a batch file to join the splitted files later. This feature is useful if you want to split your files for transport (e-mail, floppy) and your medium has a size restriction.
Furthermore, MP3 Splitter allows you to cut selections out of MP3-files by giving starting and ending time. If you want, MP3 Splitter appears in the shell context menu of MP3-files, so that you can access the tool very quickly. Please note that the program does not allow splitting VBR-files.
http://privat.schlund.de/MP3Renamer/mp3splitter.zip
Удачи !