To remove it, you'd need to have a mutator running. You'd need to edit the material for the flag. Create a new copy of the flag material, and change the opacity mask to 0.
After doing this, make a copy of the silo skeletal mesh. RX_BU_Silo.Meshes.SK_BU_Silo
In the skeletal mesh editor, set the material 0 to your new material.
After this point, you'd need a mutator to replace the internals of the Silo. You need to replace the internals, as that's the only place the SkeletalMesh can be changed at.
While this is possible, it's not really practical.