Go to CC or mod site of choice and download the files to your computer from there. You don't need WinRAR or 7-zip to actually download any game mods or custom content. To Download just the Sims 3 mods folder, click here.
Download a new Sims 3 folder with mods folder included here, from Where Do the Mods and Custom Content Go? Having a hard time getting your mods to work? Click Here Or choose to grab the mods folder already put together by MrsFlynn. This is a step by step guide into creating a Mods Folder, for anyone who has never used mods before and doesn't know where to start. Creating a Mods Folder/Installing Mods Step by Step Guide