I need to replace the rear sprocket on my '83 ATC200. I took off the left chainguard cover and gave it a lok over. Taking the chain off looks no prob. The rear sprocket looks like you take 4 bolts off and it should 'slide' right out. Kinda like it's bolted to a hub on the axle rose. Am I correct? The front sprocket looks like it's held on with a couple keeper nuts. Will this 'slide' right off or is it pressed on too? Thanks.....Matt