In just a few steps you can have any merged package folder (yes even if it is from another creator) un-merged. This is the easiest method to use when it comes to having to possibly find outdated CC clothing/accessories or objects that may need to be fixed due to it broke from a patch (such as seasons or pets).
First you must have S4S to do this. If you haven't registered yet, head on over to Sims4Studio to be able to download the tool.
Once you have S4S, launch it to get the home screen. In the Tabs click on >Content Management>Un-Merge packages
The next little screen will pop up and in here all you need to do is click on Browse to find the merged package. Once you have found that and clicked on it
For this tut, I will be using the merged file I created to use in the other tut on merging here.
Next you'll be prompted for the location of the folder you wish your un-merged items to go to.
This same box will pop up again and both folders should be listed then click on Un-merge
Another screen will pop up, you can either highlight it and click Open or exit out by clicking on the "X" button for that window.