Step 3: Hack the movement
The clock movement has a single coil stepper motor inside. The basic theory here is that we want to disconnect the coil from the clock's timing circuit and then attach wires to the coil so that we can control it ourselves.
So, knowing this, open up the clock movement and make careful mental note of where everything is (or take a picture).
Take apart the movement until the circuit board is free.
Locate the contacts on the circuit board where the motor is located. Notice these two contacts have traces that go off to the chip (hidden under the black blob). The idea is to use a razor blade or knife to scratch away at these traces until the connection with the chip is visibly broken.
For good measure, I also cut away the timing crystal, rendering the circuit more or less useless.
Lastly, I soldered about 6" of wire to each of the motor terminals.
When this was all done I put the whole thing back together. There wasn't a spot in the case where I could conveniently slip the wires through and I needed it to go properly back together, so I ended up cutting a small hole for the wires to pass through.