Raise the GTI using the car jack. Place the car jack behind one of the front wheels on the chassis itself. Use a tire iron if the jack is manual, or the lever if you have a hydraulic jack to raise the vehicle. Slide a jack stand beneath the GTI about a foot away from the outer edge on a part of the chassis. Lower the car jack so that the GTI rests on the jack stand beneath it. Repeat this process for the other side of the car.
Lower yourself beneath the engine. Look for the oil filter, which is a large, white, cylindrical object attached to the engine mount.
Slip the metal loop of the oil-filter tool around the girth of the oil filter, midway up the body. Crank it once to tighten the loop around the oil filter. Twist counterclockwise to loosen the filter off the engine mount and finish loosening it with your hand.
Note whether there are any differences between the old oil filter and the new one in terms of girth, height, and model. Spread a film of new motor oil on the seal of the new filter, which helps the filter make better contact with the engine mount. Use your hand to tighten the filter on, and finish with one last twist using the oil-filter tool.