chisel

User something other than a dowel with a smoother surface such as a thin screwdriver. The wooden dowel has too much friction.

I used to own a Craftsman trac dive and got rid of it because of the very thing you speak of...They are difficult to turn. You cannot manhandle them either.  I owned it for one year. Luckily, the next year  I was able to sell it for more than I actually paid for it because that year turned out to be a BIG snow year and there wasn't a snowblower to be found. In my opinion I would stick to the wheels.

Are you sure you have the correct shear pins for your make and model snowblower?

It's blowin' time in Massachusetts on a Sunday. It's supposed to snow all day and put down 18 inches in some spots. It's a light powdery snow in most parts and should throw a country mile! Yippeeeeee!

May I suggest...why not stop by your local dealers and ask them. Speak with the owner first and just be honest and tell him what you are interested in doing. That is a start anyway. Good luck. Let us know how you make out.