Instructions
Right-click on the .ZIP archive for your "Epic Creature" mod. Click "Extract." A new folder will be created containing the "Epic Creature" mod files. Open this folder. Click the "Minimize" button to keep the folder open but minimize it to your task bar.
Click "Start" and open "Computer."
Click "C." From this window select "Program Files" and "Electronic Arts."
Open the folder labeled "SPORE." Open the sub-folder in this directory labeled "Data."
Click on your "Epic Creature" mod folder on your task bar. This will maximize the window on screen. Drag the files from the "Epic Creature" folder into the "Data" folder. This will add your "Epic Creature" mod into the main "Spore" game.