If you're still having difficulties in removing the magnet, please follow the instructions below:
1. Unscrew the 5 screws at the back of the device. They're found at the bottom of the circular part.
2. Open the "cap" of the device.
3. Move the engine module or disconnect it from the cable.
4. Push through the inside of the case outwards using the magnet at the same time in order try to pry off the magnet.
5. Use a circular motion when trying to pry off the magnet.