1. Download: Click the download link to save the .rar or .zip file(s) to your computer.
2. Extract the zip, rar, or 7z file.
3. Install: Double-click on the .sims2pack file to install its contents to your game. The files will automatically be installed to the proper location(s).
You may want to use the Sims2Pack Clean Installer instead of the game's installer, which will let you install sims and pets which may otherwise give errors about needing expansion packs. It also lets you choose what included content to install. Do NOT use Clean Installer to get around this error with lots and houses as that can cause your game to crash when attempting to use that lot. Get S2PCI here: Clean Installer Official Site.