To install this update you need to have the 'Colin McRae Rally 3 Demo' already installed on your PC and file compression software that supports '.ZIP' files.
Unzip the file into your root 'Colin McRae Rally 3 Demo' directory ("C:Program FilesCodemastersColin McRae Rally 3 Demo" by default). When unzipping browse to the game folder, keep folder names and overwrite existing files.
This update will bring the codebase up to date with the final retail version of the game. The fixes in this update are described in FIXED ISSUES below.
Download Colin McRae Rally 3 demo patch
Source : 3D Gamers