I suppose removing is not the problem, but recognizing which images are no longer used.
But to do this, you would have to check all palettes currently in use on all CAD workstations.
And what is available but is actually not used? Will it be used again in the future? This cannot be decided automatically.
Just move all images to a backup folder and wait for the call of your colleagues.
Gruß Udo Hübner (CAD-Huebner)