You have to take out the top 2 bolts on the radiator, disconnect all the water hoses and tilt the radiator forward. The plus that should be used are NGK CR8E or CR9E. Use a new spark plug to determine what size plug socket u need. They are a real pain to get at, but once you´ve done it a couple of times you should be able to do it in less than an hour (including fairings)