One of my NYC buddies is having problems with their URSA's battery plate, so he took to EXTREME MEASURES.

https://twitter.com/mattpenndotcom/status/547159779479928834

The threads on the tiny screws were stripped, along with the head of the screws trying to get that particular part off.

https://twitter.com/mattpenndotcom/status/547161411437473792

All this to get a V-mount plate installed...

https://twitter.com/mattpenndotcom/status/547166616665227265

Those images look a bit cruelbad.

3mm countersunk screws seem to have an unhappy knack of tearing away in the hex hole. As for "seized" screws, BM may have used some sort of thread lock material, one of those damned if you do damned if you don't things. If the screws loosen and fall out, people will stamp their foot too. They have given me a headache with the SI2K camera and a Speedbooster.

For the future, you need to be sure the hex key, bristol wrench, allen key or whatever you call it, is of the correct size for the screw head. The traditional tool with the right-angle bend is impossible to control well enough for countersunk screws. You are better off buying one of the those screwdriver sets with a master handle and many small bits which come as flat blade, hex, torx and philips.

You may find it helpful to insert the bit piece into the hole in the screw head and gently rap it with a light implement to crack any threadlocker or corrosion bind on the chamfer face of the screw. If it remains bound, a much smaller flat bit inserted sideways in the hole rapped gently once to kick the screwhead edgeways a little may crack a bind free.

Make sure the bit is pressed firmly into the hex hole when you use it with the driver handle to take the screw out. If it begins to slip, you may get another chance if you press in really firmly and tilt the bit slightly off to one side by about five degrees to tighten the grip of the corners in the hole.

Rather than twist the handle with fingers, grip the handle firmly and rotate the tool using a solid wrist movement as you maintain pressure into the screwhead.

If you end up with a rounded hole, there is a torx bit very slightly larger which can be rapped into the hole which may reform the torn-out hole enough to enable to extract the screw.

The final desperation is to wrap the appliance up to keep metal swarf out and use a thin cutting wheel on a Dremel tool to cut a blade slot across the face of the screw for a blade screwdriver to do its thing.

Sudden shocks into the camera of course may do damage and void warranty so please be mindful of that possibility. Please also heed the wise words of people other than myself who offer solutions as I am far from qualified to comment on such matters.