My P290 Field Strip "solution"
I don't know where I got the idea the slide had to been in the position shown in the manual to remove the slide stop pin.
I was wrong. I must have had brain "fade". The position shown in the manual picture is wrong.
Get a cheap ballpoint pin with a "pointy cap". Or, retract the point. This is your "push pin" tool.
Obviously, remove the mag. And, remove the round in the chamber. Well, duh.
Rectract the slide until held by the slide stop.
Hold the grip in your left hand. Find a table with a sharp edge.
Hold the gun straight down, and place the muzzle end of the slide againt the table edge.
Position yourself so you can see the right side of the slide with the "little end" of the pin.
Push down on the slide as far as it will go. You will hear a little click or "pop".
Use the ballpoint pen to push the slide stop pin "little end" inward, just past the retaining spring.
You can now pull the pin out by grasping the other side (with the lever).
Place the slide stop pin in its hole. As you push the slide rearward,
gently push the slide stop pin inward and have the tab on the rear of the lever clear the notch on the slide to allow full inward movement.
Like I've said before, if it can't be done, it's because you don't know the procedure. :smt1099
I didn't know the procedure.