undo the saftey pin on the caliper like a small piece of metal. Lift the calipers up Push metal piston back with some sort of leaver or grips.
Remove old pads, Replace with new.
Open brake fluid reseviour. Pump brake until the hydrolic piston is back upto the brake. (the brake will have stiffened up)
Reverse everything making sure you put the saftey pin back in.
Tire on jobs a good n
Make sure you go easy on the brakes for a while
you did how ether overlook the finer details there like cleaning out the callipers of brake dust with some emery paper and the application of coper slip were the pad contacts the calliper frame and cylinder