Advice on Changing Pads in a Parking lot

Use a 6 point 3/8 socket, on the bleeder screw to reduce the chance of rounding off the head on the bleeder.

I replied earlier hoping that you wouldn't break off the bolts holding down the pad clips, but i guess you removed them ok without snapping the head of them off.
Those things are the ones that usually break, if your working on a car that went through lots of winters.
But bleeder screws rust up, seize up also.

I don't think you followed instructions in retracting pistons back into their bores.
You leave one side of the old pad in the caliper, to keep them from coming out, while you compress the other two, on the rotor side that your working on.
Then put in that new pad on that side, then do the other.

Sounds like you went metal to metal on the rotor(s) so your only doing a half assed job anyway by just replacing pads, without machining the rotors, or replacing them, if they are undersize.
But anyway, replacement pads will at least get you back on the road again, and at least stop, other than being metal to metal.