Use the 'Clone' feature: Find the component you want to modify in the library, right-click on it, and select "Clone". This will duplicate the component, and allow you to modify it as a separate entity without affecting the original part[1].

Alter component attributes: Once cloned, you can edit the attributes of the new part. This includes modifying the number of pins from 8 (or whatever the original count was) down to 6. You will also need to edit the pinout and labels to match the functionality of your new 6-pin component.

Update the schematic symbol and footprint: The schematic symbol (which represents the component in the schematic layout) and the footprint (which represents the component on the PCB layout) should also be modified to show 6-pins instead of 8 (or the original count). Be sure to update the pin numbering to reflect the new configuration.