You don't EVER clamp a brake hose. It gets removed via the 14mm banjo bolt. Yes fluid will drain out sadly, you can clamp it with some rubber and vice grips, or anything else you can think of. If its for a minute, you can simply re-bleed the brake, but overnight, the car CAN drain the whole master cylinder through one caliper.
The e-brake cable is connected by the retaining clip (remove with pliers, its a spring clip) and the retaining pin at the e-brake lever (remove the little spring clip with needle-nose pliers, its maybe a millimeter thick, and then remove the pin by pushing it out by hand, it will slide out.)