Now to change the front sprocket. To start off unscrew the bolt holding the rod to the crankcase and slip it off so that the lever hangs freely.
Next you need to unscrew the three bolts circled in red below that hold the cover. These bolts are not the same length, to help remember how they go I put them through a piece of cardboard marking which direction is up.
Now you can pull the cover off and you have access to the sprocket. Before you can take the nut off the crankshaft you need to straighten out the washer that is bent over the nut.
Once the washer is straight you can begin to attempt to unscrew this nut. That sucker is on there tight. With the bike in first gear and my dad holding the rear brake the wheel still kept spinning and the nut wouldn't unscrew. To stop this I took off the chain guard and placed a 2x4 over the swingarm through the tire.
After that it was fairly easy to get the nut loose. It is now possible to pull the sprocket off and to place the new one on. When swapping the crank sprocket the service manual says to lubricate the new sprocket and crankshaft with molybdenum disulfide. I used some moly grease and put the sprocket on.
After that I placed the washer I took off earlier back on the crankshaft and tightened the nut. To keep the wheel from spinning while tightening I used the 2x4 again but this time I placed it under the swingarm. I tightened the nut 94 ft-lbs, according to the service manual.
At this point you're pretty much done. All that's left is to put the cover and gear lever back on. Then you need to adjust your chain and tighten the rear axle.
I haven't gotten any significant saddle time with this set up and probably won't still spring time but the short test run I took had me wishing I've done this earlier and these bikes should definitely come from the factory with a 15 tooth sprocket up front.
With this set up my rpms dropped by about 1000, a little less I'd say but I was able to travel on some of the roads I've taken before pretty much a gear lower. Setting up for corners I was able to stay in the same gear and have enough power to drive through the corner. Before I was either getting close to redlining driving through corners or I'd have to grab a gear up to drive out of the corner.
EDIT: Since this DIY was published, a number of folks have come to the conclusion that the spacer side of the front sprocket should be facing in, not outwards as shown in the last picture