Hi, I'm having some troubles when modifying the mass properties of a part. I've received the .STEP, open it, and saved it as a part, in order to use it on my custom assembly.

Since the part has not the correct values of mass, I want to modify the mass value to the real one (the one measured on the lab) withoutu overridding the CoM and CoG , thus, I go to:

- Materials>custom Material> and change the density of the material (by a pre calculted density, taking into account real mass and part volume).

When clicking mass properties again, the mass has not been changed and a message like this is shown:

Message: The mass properties were copied from an assembly when the assembly was saved as a part. To update the mass properties, please open the assembly and resave it as a part.

How can I update the mass value?