Hi
You must have a soft to save the replay in video format. You can use "FRAPS" (look on Google) or an other soft who can made this.
To record a replay in video format, before starting your game, spears software (FRAPS or another), open your game (RSCenter) in single player mode and choose the right car pack, good mod, etc ... then, click the button "Start RichardBurnsRally_SSE". Once in the game menu, choose "Profile" and then "watch a replay". While watching your replay, you record the video.
With Windows moovies maker, you can reduce the file size, or add titles, etc. ....
You can then distribute it on Youtube
Regards