Even if you were the one who fitted the new discs, tyre, or headlamp bulb, you still need to run the mot re-test as if you didn’t. That means getting the car back into the MOT bay, logging the mot re-test, doing the Roller Brake Test, headlamp aim check if needed, and then updating the MOT log. The DVSA don’t make exceptions just because you trust your own work, they expect the mot re-test to be done properly and recorded under MOT conditions.