You can use Content Builder to modify an existing block-based part. You can modify the entire part family or an individual part size. Once the part has been saved to a catalog, any modifications you make using Content Builder are made directly to the source files stored in the catalog. You can modify the 3D model block and/or symbol; you can also modify the model and schematic symbol of the part size. You can redefine a part size based on a new 3D model block and reassign the schematic symbol of a part size based on a new symbol block.