Is there a special tool to remove the screws? Seems like a typical phillips, I tried them all, and is not the right fit.
Yea, 50+ years ago, it was a typical phillips. Now it's a very rusted phillips. You might make some headway if you can pick out the rust deposits that have accumulated in the screw head with an awl, allowing the phillips bit to fully engage. You might succeed by using a impact driver - the kind you whack with a mallet.Seems like a typical phillips,
If you try this route, what I have done that helps is to use some white silicone and fill in the valley/recess around the screw, and just up on to the the sill top area, (sorta creating a donut of silicone around the screw). Then, when you come in with the dremel, you can see where the wheel is cutting a little better, while providing protection for the sill surrounding the screw. Once it off, the silicone will usually peel right off, but any residue will clean up with citrus scrub cleaner without any scratching or damage to the stainless.If you can get a clean shot at it, the cut off wheel on a dremel can turn any phillips into a slotted screw - just cut a slot across the head. I do it all of the time. In this case it may be too recessed into the sill and you risk the the cutoff wheel damaging the trim. Alfajays suggestion plus the grind compound may do the trick though
FWIW, I wasn't implying that route as a preference, and certainly not to save the screw. Typically I would drill the head off too, but I have slipped when doing this before as well, and damaged surrounding material. Sometimes I choose the method of cutting a groove into the head of the screw, and then use a blade screwdriver to back it out. I wouldn't say I'm brave...Wow, you guys with the cut-off wheels are braver than I am. I'd sacrifice the screw in a heartbeat before risking damage to the ss trim. Drilling off the head of a phillips screw, as divotandtralee suggests, is pretty foolproof.