Am trying to take off the front passenger side brake disc. But who ever put the disc on last time rounded the head on the screw that hold the disc on

so i drilled the head of the screw.
But the disc just doesn't want to come off

tried giving it a bash but still aint playing

. The caliper is off, so is it just that wee screw that holds the disc on or am i missing something? Or do i just need a bigger hammer and hit it harder ?
