Here is what I did recently to fix my 4th Gen PO ......
It had 6 lume dots that came off and were floating around the dial.
1) remove the case back. Use a sticky ball or duct tape rolled up into a ball
2) Remove stem - search how to do this - my only tip is when you push the stem release button, do not push too hard! Just barely push when pulling the stem out.
3)remove either the movment ring or retaining screws, turn watch over and let the movement rest in your hand. Wear gloves!
4) place the loose lume back on the marker with a very, very, very small dab of epoxy.
5) let the epoxy cure over night before you re-case the movement. Or the fumes might ruin your dial. Just keep it in a dust free ventilated place.
6) put the it back together in reverse order - make sure you check the crystal for any lint/dust or you will have to repeat.
Good luck. And if any of this makes you queasy, contact Katt or 14060.