There is a program out there that can transfer files from your computer to your Yepp player. Here
it is. I didn't look around too much but I think it should work with your mp3 player. You'll probably need to compile it from source so here's how you do that.
1. Make a directory called sulu in your home directory and move the file you downloaded from the site above into it.
2. In a console, type 'tar xfzp filename.tzg' where filename is the name of the downloaded file. This extracts the contents of that file into the current directory, similarly to a zip file in Windows.
3. Type 'make' and wait until every thing is done scrolling and you're back at the command prompt. You now should have an executable called sulu in that directory.
The site says you'll need to run sulu as root or check note3 in the note directory, which will be one of the files you extracted earlier. Hopefully this will work for you and you can use your mp3 player.