help clone a cc from the internet to a new cc

hi i'm beginner in modifying with cc and don't know sims 4 studio as well again.

i have downloaded a ceiling cc from the internet.



but since that ceiling is only 8x8 large I will convert it to 10x10.

i took the original cc and made a copy of it and then export mesh and texture to my pc so i can go inside the blender and scale the mesh up to 10x10 and then inputting it back to my new cc file in sims 4 studio. and then make it to a new cc
.

So when I go inside sims 4 I can see my new cc but original cc disappears what am I doing wrong ???

will be so happy if you can help me