I got a 12 tooth sprocket to replace the 13 tooth to play around with the gearing ratio, but noticed a special tools is suggested and the manual recommends the clip be replaced. Any work arounds to use some other tool? Does the clip really need replaced an time the sprocket is removed? It looks as if the star nut (?) just come off like a regular nut, but require this special tool to turn if off, correct or no?