Replace the files contained in the archive to the game files.
Be sure to make a backup copy
If you are planning to create their own liveries use folders: livery_29/30/40/41/44 they contain the standart blue model.
(№1 in the game "livery_00" - blue livery of stock)
(№3 in the game "livery_13"- black livery of stock)
(№4 in the game "livery_25" - livery WRC 2006)
mod not working in on-line