The left SMAS my 8kx came with had an overtightened screw which lead to the screw getting badly stripped beyond repair as I was attempting to remove it to replace it with the DMAS.
I was about to open a ticket but couldn’t be stuffed waiting for longer to get a replacement headstrap so I attempted to resolve the issue myself.
The approach I found to be the most effective was to use a center punch angled on the rim of the screw to loosen it.
Once it dug in after a few taps I was able to unwind the screw.
You might end up injuring yourself if your hand slips or damaging the product so I do not recommend doing this unless you are willing to take the risk.