Bench Bleeding my Master Cylinder and...
That little sucker can really stick in there. Great design, really – a lot of bang for the buck from a tiny piece of rubber.
When you disassemble it normally, you loosen up the M/C attachment nuts, shim out the M/C from the firewall a bit, then go inside and give the brake pedal a HARD pull backward to dislodge it.
In your case, you'll have to create a similar system, or possibly install it in a car, shimmed-out, and use the brake pedal to hammer it out. That may actually be the easiest thing.
I usually just use the handle of a hammer to bench bleed. Anything that will fit in the hole will work fine, and I prefer to use something non-marring.
– Eric