Help Stripped head

I have a 79 KZ650 C3 and I was in the process of taking out the starter clutch to repair it. I was trying to take the oil pump out and loosen the 3 bolts on the bearing stop (they are phillips heads and are staked) I used a manual impact driver and it striped the head) any ideas? I am talking about the one on the right side below the clutch.

Maybe you could try a small cold chisel and a hammer to break it loose.

i usually take a larger star bit and hammer it into the screw head making a inpressing of the star and the hammering will loosen it up. or there are special tools like the grab it that pulls out stripped screws.

Could you possibily do this, find a drill bit slighly smaller then screw head, now the key here is the next statement slowly in reverse drill the head till its weak enough to be removed from what ever its holding, now I say reverse and it is a pain but it works and it will not bite and wreck cover or what ever its holding like it could in forward.( and does I know, its faster in forward but if it bites in you WILL wreck both pieces trust me I KNOW!!!!).