Ya man I know it's gonna be a mess and it sucks because there's not a single video of someone changing that out to follow and do myself lol because don't really wanna pay 6 or 700 for labor and thats if I walk in with the motor out the bike they said..^^^^ And that friends is why you don't buy cheap front sprockets.
K5gsxr42, you need to sit down for this.... you need to open the crank case and replace that shaft. In doing that, you'll also want to replace the bearings for that shaft and possibly the bushings as well. It's not going to be cheap. Alternatively, you could go completely redneck and weld the new sprocket to the shaft and accept that the next time it needs changed will have to be cut off. I recommend fixing it correctly.