Peeling-off of an oil-repellent film can be reliably prevented. The method includes determining whether a current shift range is one of forward driving shift ranges, calculating a minimum line pressure based on at least one automatic transmission operating condition if the current shift range is one of the forward driving shift ranges, and calculating a solenoid duty ratio corresponding to the calculated minimum line pressure. The tool comprises : a directing structure adapted to engage the second surface of the sash ; an application structure pivotably coupled to the directing structure ; and an element for biasing the directing and application structures toward one another such that the directing and application structures are capable of being releasably clamped to the sash.