After some testing this is the best way to attached the backing plate on the 2nd Generation foam pads.
1st tip in the backing plate edge on the black inner "L" lip of the back like picture shown.
2nd bring down the rest of the plate so the backing plate is fully in the black āLā lip like the picture.
Lastly press down on the PC head like the picture shows to ensure the backing plate hooks latch on the loops on the fabric.
I tried numerous methods to mount the backing plate and this method was done with one hand.