You set the engine to TDC, disassemble the injection lines, unscrew the plug from the injection pump head, install the mounting with the sensor in place of the plug. The sensor is mounted with initial tension of about 2-3 mm, you turn the crankshaft in the opposite direction than when the engine is running, observing the sensor indications, turn until the sensor reaches the lowest point. Now you zero the sensor and start turning the shaft in the direction of normal operation until the marks match at engine TDC. You read the value from the sensor and compare with the assigned value, if the value is within the range, adjustment is not needed. If the value is out of range, you loosen the pump and gently turn it left or right until you reach the correct value on the sensor, tighten the pump and check the setting again. I will not write you the value of the stroke of the distribution piston because you have not given any data about this miracle.