In all circumstances, I strongly advise that the original files are backed up before installation of the new files begins.
ReadMe.zip - An indepth Readme file concerning all of your troubles with installing the following files. Download the Zip file (49k) or read it online HERE.
Sounds.zip - SDT files used for sound effects - extract to GTA/GTADATA/AUDIO/- 3.7kb
Fxts.zip - Fxt files which change the names of the vehicles in all cities - 99.4kb
Patch0.zip - Raw files, Pre-Game Graphics - 2.57mb
Patch001a.zip - Style001.g24 - City1 Hi Res graphics - 1.53mb
Patch002.zip - Style002.g24 - City2 Hi Res graphics - 2.07mb
Patch003.zip - Style003.g24 - City3 Hi Res graphics - 2.11mb
Installation Procedure
To install these files simply unzip and copy to the GTA/GTADATA directory.