I have done a gen 2, probably the same or similar. This is from memory, so don't blame me if its wrong.
Remove front sprocket cover, Loosen the front sprocket retaining bolt.
Slacken the rear wheel and wind the adjusters off so that the wheel can come fully fwd.
On my bike ther was enough slackness in the chain to waggle the front sprocket off, if not lift the chain off the rear sprocket to give yourself some more slack.
New sprocket in, chain on, retention he chain etc.
Don't forget your gloves, it's a mucky job.:thumbup