According to the online A2 manual
It is not difficult do disassemble the bit if you knowhow.
Some disassembly of the distributor is required to replace the Hall sender. It will require a snap-ring plier and. It is possible to disassemble the base plate, the distributor shaft, and the centrifugal advance mechanism, but these are not available as individual replacement parts
Trigger wheel being pried off of distributor shaft. Pry evenly under center of trigger wheel, from both sides with two flat-bladed screwdrivers.
Use a snap-ring plier to remove the snap-ring retaining the trigger wheel. To remove the wheel, use two screwdrivers positioned at opposite sides of the trigger wheel to pry it up as shown in Fig. 5-6.
|CAUTION- Push the screwdrivers in as far as possible, and pry up only under the strongest, center portion of the trigger wheel. Take care not to lose the small pin which keys the trigger wheel to the shaft.|