Opening the ASRock 4x4 Box case

I have a barebones mini-PC kit that I want to use and I can't get the case open. There are 4 screws with 'Frearson' heads on them. The cuts in the screw heads are so shallow that no Phillips screwdriver will work on them. The screws are about 1.5-2" long and very very tight. I tried a small flathead driver and it doesn't work. I need something like a Standoff driver but without the projecting spike in the tip and with a handle long enough to give me the leverage to break an apparent loctite bond.

I wrote to ASRock support and got no response. Also called them, and called the seller. No one, even my most experienced geek friends, has been able to help. What do you recommend?