Pre Existing Sims: Ever wondered how to edit pre-existing Sims in Sims 4? Other than being able to customize your surroundings like the university you attend or the home you live in, you might want to make some changes to your character from eye color to their personality.
At a glance, this may not seem possible, but this article is here to show you how to do exactly that and customize your Pre Existing Sims however and whenever you want!
How Do You Edit Pre Existing Sims?

The only way to edit your sim once created is to enable and use the cheats console built into the game. Depending on the system you’re playing on, the way you do this can differ but the commands you’re going to use will remain the same.
After that, you will enable the CAS (Change a Sim) options in your game and you’re all set to start changing your sims however you like!
Enabling Cheats and CAS on PC
First off on PC, while in-game you’re going to need to hit Ctrl+Shift+C. This will bring up the cheats textbox on the top left of your screen and allow you to enter the cheat commands.
From there, type “testingcheats true” (without captions) into your cheats console.
The second step is to enable the CAS (Change a Sim) edit mode. In your cheat bar, type “cas.fulleditmode” (again, no captions) into your console. Now you’re good to go!
Hold shift and click on a Sim. This will give you the ‘Edit in CAS’ option or head over to any Mirror in the game and select the ‘Change Sim’ option.

Enabling Cheats and CAS on PS4 and Xbox One
On PlayStation 4 and Xbox One, you’ll need to hold down all your bumper buttons (L1, L2, R1, and R2). This will bring up the cheats console as well, from there hit X or A to bring up your Keyboard.
Enter the same commands as used on the PC above. Once you close your cheats console, on PlayStation 4 hold down O and X (making sure to hit O first, then X). This will bring up a “Modify in CAS” option and you are ready to start editing.
The same applies to Xbox One, only using the B and A buttons respectively to open the “Modify in CAS” option.
The CAS (Change a Sim) feature will give you the freedom to edit your pre existing sims in The Sims 4 in any way you want at any time and we hope you’ll have loads of fun doing so!
Using CAS is a good way to create a perfect sim. But there are a few more tricks that will allow you to make the perfect worlds in The Sims 4: