I think this could be done in the Event Inspector Module.
Remove an unneeded module in the Control Bar by right clicking on it and select Hide Module.
Right Click an empty space on the Control Bar and select Event Module Inspector (it should appear in the Control Bar... if not you need to remove another module because the Event Inspector is kind of big).
Open the PRV for that drum track (select the clip in the Track View then go to Views at the top of your Sonar window and select the Piano Roll View)
Then in the Piano Roll View right click and drag to lasso all the notes you want to change or select them some other way.
Punch in the note value for the sound you want to change those notes to in the Event Inspector Module and press Enter.
...
I think that's how it's done. I watched Scott Garrigus perform something similar in a Digifreq video he posted the other day.
But yeah... lots of ways to do this. That is just one.
Cheers.