Hi Jeff,
I just did this. Insert the the key and turn it to the on position so is at 90 degrees. On the barrel there is a 1/8" hole. When you turn the key you will see a brass pin at the bottom of this hole.
Using a small Philips or push pin about 1/16". Push the pin in and keep it pushed in, it's on a small spring. Using a screw driver say then pry out the cylinder. Pry against the key and the edge of the barrel. Once you pry it out a little
not easy, you can release the pin. Then pry it out the rest of the way. When I did this the spring and pin piece came apart, very small so do it over a table. Also mark the positions of the cylinder and barrel before you take it apart. Later Dave Walsh