I have a quesiton... More than once I've had to resize the opening where the propeller comes out of the spinner. Fore example, i have a GP RV4 and it calls for a specific size of spinner. The prop that i am using is too big for that opening.

The question is what's the best way to open the holes where the prop comes out of the spinner? i normally just use a knife and start cutting until the prop fits. I am sure someone here has a much better and maybe a "right" way to do it.