The casing comes apart in two pieces and the actual copper coil comes out from inside. You need to remove a locking pin from the bottom of the motor.
Is the pin that U-shaped thing?

Any ideas on what tools to use to remove it?
Also, the jacks connecting the wires to the motor are under the black insulation, right? Did you cut it to unplug the motor? Or just hold the black thing and pull the motor?
Thanks for your posts and pictures, they're very helpful. I got some sand in two of my motors and I wanted to try opening and cleaning them before I get the spare motors from the dealer (installing which will also be tricky, I believe).