Harman Kardon Citation 12 input amplifier

so we have that in common, the cars and for me also the motorcycles.
something that works very well for damaged cruciform screws, it's an electrician's straight cutting pliers, I take the head from the front with it, I tighten it with the pliers to mark the head and when the borrowing is sufficient, I squeeze hard and I turn, it works in most cases (when there is a head left to tighten)
 
I work on my cars too..crazy need to fix all things myself! and when a philips screw stripped I cut a slot in the top and used flat screwdriver to remove..
Maybe will try the same here
Thanks for your help

Use a Dremel tool with a cutoff disc and cut a slot. That would work better than what I used to do with the cheap reverse-hex pot metal bolts on car interiors - I'd cut down the bolt heads with a grinding disc until it had two flat sides, then I'd use a crescent wrench to turn it. :cool: