Brake bleeding is done by two way... One is manual bleeding which needs two
people to do the job. The other one is pressurized method in which you
attached a device to the master cylinder reservoir with extra brake fluids
and pressurizer (there is also a vacuum method).
The first method is most common... One person would sit in the car... pump
pedal a couple of times and then hold the pressure... while another person
would crack open the bleeder while the inside person continue to press the
pedal until it goes down. (Do NOT force pedal all the way down once it stop
or otherwise master cylinder is damaged)... while pedal reached the bottom
position, the outside guy close the bleeder valve and then inside person
repump the pedal. and repeat. It takes a couple of times to get new fluid to
come out per caliper. You must make sure you replenish brake fluid and keep
cap tight during the process.
The pressurized or vacuum method is one person job. and you just have to
make sure there is always plenty of brake fluid available.
Dragging brake is a sign of contamination in brake system which swells up
the seals and/or the brake hoses. You either replace the caliper with a
rebuilt one or a new one to fix this problem. In this situation, it is
possible your brake lines are also damaged. Try bleeding brake again to see
if this solves the problem.