This is how I do it, it's the correct fix and it's pretty fast and easy:
Working below the playfield from the bottom side:
Use a 1/4" or 3/8" plug cutter below the playfield exactly where the screw is and center it.
Drilling a 1/32" hole right next to the screw all the way through helps to locate it. Try to drill very straight, or just measure it accurately.
Use a drill guide or a piece of scrap with a hole drilled into it for support it really helps to keep the plug cutter from dancing about..
Cut the plug to about half the way through the playfield.
chisel out plug and remove screw with needle vice grips.
Fill hole with a plug or dowel or just leave it inset for the t-nut. (I use a plug cutter that is slightly larger than the t-nut diameter and usually I just clean it out a little and leave it inset for the t-nut).
Drill new hole for t-nut (or screw if you filled it with a dowel).
I epoxy the t-nuts in. This firms up the area a bit and holds the t-nut.
I install t-nuts with an allen bolt thru a fender washer that has a bit of stick on felt to protect the surface.
Cardboard will also work.
It works very well.
