Use mods at your own risk!
Your mod should be a .package file.
----------Windows XP, VISTA, 7:
Spore mods are usually placed in this directory:
C:Program FilesElectronic ArtsSPOREdata
Some computers use:
C:Program Files (x86)Electronic ArtsSPOREdata
Most mods only work for Galactic Adventures, an expanison to Core Spore, but some were created specificly for Core Spore. So make sure to read any details, forums or readmes about your desired mod.
GA directory for mods:
C:Program FilesElectronic ArtsSPORE_EP1data
C:Program Files (x86)Electronic ArtsSPORE_EP1data
The Spore.app is an application package, so you’ll need to control/right click on it and select “Show Package Contents” from the contextual pop-up menu, which will then open a window where you will then see the “Contents” folder, so navigate the rest of the path mentioned above.
I believe that the GA folder on a Mac would work just like its PC counterpart.
I have never found any tutorials on how to mod Spore. It is a matter of trial and error.
On the bright side, here are a few popular mods created by myself.
Other popular mods are created and posted on the Sporedum
http://www.sporedum.net is/has closed on May 11th 2010. The mods found there can now be found here!
If you cannot save a creation, try the forcesave mod. You can find it at either of the links above!