1. Download and install Codemasters Custom Tracks Thingy.
2. Run the Codemasters utility on the PC, select mp3’s from the hard disk or a music CD and convert to .toc
The file will be something like "example.toc"
3. Rename the file to "example.gta"
4. Make a folder called ULUS10160CUSTOMTRACKS
5. Put all .gta files in ULUS10160CUSTOMTRACKS
6. Put ULUS10160CUSTOMTRACKS in your gamesaves folder.
7. Start GTA, select custom soundtrack in audio options and enjoy your own music.
8. If you have custom tracks still from LCS just rename the folder to ULUS10160CUSTOMTRACKS and drop it in the gamesaves folder.
Pretty much like the old GTA. But will save some questions.