about 2 to 3 days in advance. Spray it on every day, let it soak. On day two wiggle your socket down on the sensor and try to give it a turn just to loosen a bit. Both directions. Spray more Blaster then let it soak over night. Repeat next day. Patience will be your friend. In the end, it will still take some elbow grease but the more prep you give it with the Blaster the easier it will come out.