A Flathead screwdriver
A sharpie marker
And a golf ball
Step 1: Marking a Line
Then take your saw and cut along the line until you can see a different color inside the cut, do this all the way around the ball.
Step 2: Prying Off the Shell
(BE CAREFUL IF THE SCREWDRIVER SLIPS OFF THE BALL AND HITS YOUR HAND IT HURTS!)
Once you get the screwdriver under one part of the shell shift the screwdriver a bit to the left and continue prying. Do this until the shell pops off.