Sonance Mariner - How to fix grills falling off

I have Sonance Mariner 86 speakers, have had them for 6 or 7 years and the grills constantly fall off. I have tried everything there is to try, including black duct tape, and they still fall off. I'm going to show you how I got them to stay on permanently.
Required:
Drill
5/64 drill bit
#4 3/8" screws (2 per speaker)
Counter-sink bit (optional - just looks better flush)

[@BacardiRum1862]

How good do 8 sound

[@BryanMack]

I don't run 8 together, they are in 4 zones spread among front porch, garage, kids playset, and backyard seating area. I use sonos, rarely have more than 2 on the same zone at once, but meets my needs!