Forum Discussion
@Mahc4 Bring up the cheats console (crtl-shift-C) and enter "testingcheats on" without quotes. Then enter the cheat "cas.fulleditmode" without quotes, and you should be able to shift-click on your sim and select "Edit in CAS." That gives the usual range of options you see when creating a sim.
@Mahc4 If you upload to the in-game Gallery you should state in the description if you used cheats on the sim, to inform the ones who wants to download.
I believe there is an option on dressers and mirrors to Change Sim, that will bring them into CAS with more options to modify.
Edit: Thought of something else as well: If you save the sim to your own in-game library, and then import them into another new save by replacing the starting sim, I think most if not all options are free to modify, and that new version you can then save yet again. I am sure there are more options, if you just play around in the game. Perhaps other have more tips.