You can try just unscrewing the case and removing the front cover and see if that helps. The front cover is just a filter that only passes infrared light (and keeps dust out). But if you damaged the sensor inside, then you'll need a new Wii remote. To unscrew the case, I believe you need a tri-wing screwdriver, which you can get at Ebay. If the sensor is damaged, you can sell the remote to a hacker who only needs it for the accelerometer.