Use the Philips screwdriver to remove the 4 screws hold the ignition module back plate on. The black gizmo on the back cover is the Hall's pickup.

Open the back plate and use the small flat blade screwdriver to remove the 5 screws holding the circuit board to the ignition module housing.

Get the screw at the top middle (previous photo) and screw at each corner. All have a washer and lock ring.

Remove the circuitry from the front cove. You can see the heat sink plate at the top of the front cover.

Here's a close up showing on the left the high power integrated circuit that sits on the front cover sink plate. The LED bulb is the red bit on the right.

You can get heat sink paste at Radio Shack.

Put a pea size dollop on the heat sink plate and reassemble and reinstall the ignition module.