First of all the sheet metal part was inserted into the forming operation using the previously used guides and digitized. From the scan, we were able to determine the exact position for the fit of the new fine guide so that the sheet metal position is identical to the original. This eliminated any discrepancies between the design data and the tool. As the previously determined position of the new guide is between two tool inserts with different material hardness, it was necessary to produce the cylindrical cut-out in two steps, as different process parameters are required due to the change in material. First, the hardened insert was dismantled, and the machining was carried out in the comparatively soft tool steel. Suitable milling tools for machining hardened steel (> 60HRC) were then set up and machining was completed using suitable tools and parameters. In addition, the necessary milling was carried out in the upper part of the tool. Finally, the function of the new guides was tested by installing the old and new guides at the same time. The sheet metal part was inserted and checked to ensure that both the old and the new guides were in contact with the sheet metal part, thus ensuring correct positioning. Finally, the old guides were dismantled and some sheet metal parts were produced using the newly installed guides. These were checked by customers for quality and dimensional accuracy and found to be free of defects. By removing the hole punches, which punched the previously used holes in the sheet metal part, the customer modification was successfully completed.