Bill,
Yes I used ECM spy to set the timing. There's an explanation in the ecm spy instruction or just follow the service manual. Yes drill out the rivets on the outer cover. There will be a solid plate behind that held in by screws, remove that, the timing "plate" will be behind that.

Swiped this from an old post over on badweb, condensed version but gets the idea across. Don't worry about step 3 you'll be reading that in ECMspy.

Timing setting per FSM [ CONDENSED ]

1. Set front cylinder to TDC on compression stroke, (a mark is visible in the plugged hole right side base of cylinders) to align for tdc be sure that it is the front cylinder

2. remove rivited cover, loosen pickup mount plate to allow movement

3. connect volt meter to pins 3(+) or 7(-) on the grey plug, while still mated to ecm
(from back)

4. move the timing plate until the reading changes to + 5 volts from about 0~1 volt
this happens when the timing cup edge passes the sensor switching point

5. when set, snug screws then re assemble.

This is the static timing set, }