agreed, just unbolt it, hang on to the hardware though. Throw it in a 5 gallon bucket with some Simple Green or a comparable degreaser and fill it with water. Let it soak for a few minutes then loosen the dust and oil and debris with a rag or sponge. You can clean your air filter the same way, but i would highly recommend using Spectro Foam Filter Cleaner and Spectro Filter Oil (just follow the directions)
Also, i heard you can use some mild silicone to seal it up.....go down to the hardware store and find a clear-coat aerosol silicone that will work as a sealing adhesive. Go easy on it though.