How do you get crumbling screws out of door sill?

Of the 12 screws holding the covers on the door sills (4 on @ front door sill, 2 on @ back sill, 8 are so rusted out the first one crumbled when we tried to remove it & the other 7 are going to do the same thing. We're afraid to try to drill them out for fear of drilling into a cable.

Strangest thing is that 2 of the 4 on each front door sill--Numbers 1 & 3 counting from front to back--are sound, glossy, black-coated screws. All the others, back & front, are rotten.

Anyone know (1) how to remove the rusted ones safely, (2) where to get 8 more of the good black-coated kind , (3) how to install the new ones to seal against moisture?

Break them out, there should be enough left over to grab them with a good set of linemans pliers. Once removed take a good one down to a good hardware store and pickup a new set of stainles, put some antisieze on them and put them back in. Then spray the seals with silicone spray or rub silicone grease on them around the door... Or you can pickup one of those 'Bob Villa' specials from sears that he advertises all the time...

Drill JUST THE HEADS off the screws. Then the sillplate will lift off the remaining screw shanks. Then use a vise-grips to remove the remaining screw body.

Replace with STAINLESS STEEL screws.

I´ve drilled the screw heads off, was often hard, to keep the drill straight and those self taping door sill screws, are hard. Have used a small hand grinder (cone tip) and a pump sprayer to keep things wet, so the plastic doesn´t melt.

What if I just let my very hot 17 year-old granddaughter take the car to the nearby body shop & see if she can talk that young man into taking those screws out for free?

Works for me, I send my 20 year old daughter, down to the autoparts store all the time. Last trip, she came home with a couple of brake drums, the parts guy, forgot to charge her for. :eyes:

you better watch... the 17 year old flunky working at the shop may want to take it out in trade...