Broken K frame bolt removal HELP!

Weld the K frame on.
I'm glad that's clearly in jest so we don't have to label 'worst advice on the Internet'.

OOTB, If you have the room, an 1/8" hole drilled in the side of the frame at the bolt locations may allow you to saturate them with PB Blaster.
I would've posted this first if my reply hadn't taken a half hour to type on this phone.

Just keep stepping up drill sizes until you’re close to the edge then take a chisel and knock out the rest, after chase with a tap

Normally I'd agree but you don't want to risk breaking the weld on the nut holding it in place and you don't want to bungle those threads.

IF you chase it with a tap, use a good tap and coat it with antiseize. Work slow and don't crossthread that *****.

And antiseize ALL THE THINGS on reassembly. Follow the manual for torque spec, NO impact guns.