Trouble changing brake pads
 

I have a 2007 GZ250 that I bought used 4 years ago. I have never changed the brake pads before and I removed my front brake caliper. My problem is that the skinny Allan pin that aligns the brake pads wont budge at all. I'm not sure what to do with it.

On top of that I cant remove the bolt that connects it to the cable/hose to the hand brake.

The bike is kind of rusty, I'm not sure if there is anything I can do to lubricate it or potentially (in the case of the pin) can I come at it from the other end somehow?

In frustration I have bought a new caliper on ebay ($40) although that wont help me if I cant disconnect the existing one from the brake hose.

Any tips?

Penetrating oil may work. Leave it to soak for a while, then see if that worked. If it doesn't, another way is to apply heat, either from a blowtorch or welding torch. As you've got a new caliper, it doesn't matter if you damage the old one, as long as you don't over heat anything else in the vicinity that you might damage or want to use again.

There is the method to dissolve the bolt from alu housing if you don't care about the bolt. Follow link for instructions:
https://www.youtube.com/watch?v=fqZYgReuywM