My magneto piston is toast. I've replaced the rear cylinder in the past and the bolts for the exhaust thingy are easy to access so that cylinder was easy to get out. But for the front cylinder I can't access the 3 bolts for the exhaust thingy. Does the exhaust need to come out? If so, I see it has 4 bolts on the top end and then a hose clamp on the bottom - is that all there is to remove the exhaust?