Forum:Installing Mods for Sims 2 help?

Hello, I am a random sims 2 player. I really want some fellow player advice on how to correctly install mods. I have tried to install a few mods off mod the sims, but nothing shows up in game meaning nothing has been installed. I have Winrar, and when I downloaded the mod files, I placed the already compressed files in a newly created downloads folder (with a capital D), but nothing is happening. The specific mods are mods which allow me to recolour the witch's cauldron off the sims 2 apartment life and one that stops new social class townies being created. Really could ask for some friendly help and advice please!