Idle air screw head stripped off

[Guest]

I have a 1984 Aspencade that I just recently purchased. This bike has been ridden very infrequently over the last several years and as a result needed to have the carbs taken down and cleaned. Unfortunately, one of the idle air screws was tightened down all the way and frozen in place ( which also explains why the bike was running better of the choke was slightly on all the time). The end result was that the head of the screw is completely stripped off.

Does any one have any solution or ideas on how to remove it?

Thanks