Well, since everyone here forgot that there are people out there who don't devote their life, blood and souls to a fuckin' machine, guess I'll be the one to pick up the slack:
If your computer doesn't have WinRAR or BandiZIP, get one of those first (I recommend BandiZIP because of localization handling). Then you right click the RAR folder, 'open with', set it to BandiZIP, click on the folder you want extracted and click extract. Choose the location where you want it to be extracted to and then ok it and wait.