How hard is it to replace the distributor Hall effect sensor?

'92 Tbird, 3.8L V6

After 164k miles, or so, the car wouldn't start.  No spark out of the coil.  
Replaced the Ignition Control module, and nothing.  Careful inspection under the Hall effect reluctor wheel found a little metal clip and a small, loose powerful magnet.  When I removed the reluctor wheel I found scrape marks on the inside of the wheel tabs.  The down stream side of the hall effect sensor housing (plastic) was blown out and the magnet and clip were loose inside the distributor housing.  

How hard is it to replace the sensor?  Does the distributor shaft come out?
Has anyone ever seen this before? Can I save the engine timing?

My first attempt will be to epoxy the magnet back into place, but the plate on the shaft is pressed on and so access to the plastic housing is not good.