In the first part diagram, you'll remove the reed valve covers, the reed valves themselves, and replace those with your coasters. Parts 11012a and 12021. With the thinner coasters, you may need shorter bolts to avoid bottoming them out in the holes. I grind them shorter. I've seen people snap them off in the heads from not doing this.
In the second diagram, you'll remove everything in the central outline. This leaves an unfiltered hole in your intake. Plug that. A good duct tape should last quite a while.
DO NOT leave the grommet in place! I just worked on a bike that had crazy carb problems after I did a meticulous rebuild on them. It had somehow sucked that grommet down the intake after a DPO coastered it. After I replaced the carbs, it made its way down further and propped one of the slides open. Could have gotten sucked down the intake and bent a valve if the throttle plate had been open further.