Srs Air Bag Light,unplugged By Accident

I was looking for my horn one day to replace it and I accidentally unplugged the air bag sensor under the left front fender well. The key, I believe, was on but the car wasn't running. I immediately plugged it back in after I turned the key off but the SRS light won't go off. Mitsubishi wants to charge $35.00 to reset the computer but I wanted to know if there was any to reset it myself. I've already tried unplugging the car battery for a couple of days but that didn't work.:( :( :( :( :(