: Desoldering the 3-pin potentiometers and replacing them, a task that requires steady hands and a heat gun.
However, sharing or obtaining specific schematics, especially for devices that might be used in potentially sensitive applications (like vehicle tuning which can affect safety and emissions), requires caution. jdm-040 schematic
These PCB scans are often the "next best thing" to a schematic for physical repairs. : Desoldering the 3-pin potentiometers and replacing them,
Given the lack of context, here's a generic text you could use as a starting point for your search: sharing or obtaining specific schematics