You will need to extract it first using SimPe.
Here is a tutorial explaining how to do that, only follow the Step 1 part:
Tutorial-Giving your in-game sims a permanent make-overIf you do not already have a sub-folder called "savedsims" in your sims2 folder you will need to create it before you extract the sim.
Once it is done, just look in the downloads section and check the info post on what info you need to supply and how to upload sims on this site.