Push the caliper pistons fully in.
Pour fluid from the top and watch it always so it never runs out of fluid during the procedure.
Turn the bleeder on the caliper counterclockwise 3/4 of a turn.
Have a tube attached on the bleeder with its other end in a bottle.
Press the lever once all the way in. Hold it pressed.
Close the bleeder
Release the lever
Repeat until no air bubbles comes out of the bleeder.
You should already feel a little pressure on the lever.
Now start pushing the lever 10 times (pressing the master cylinder) and on the last one, hold the lever in and open the bleeder. Close the bleeder and release the lever.
Repeat that until no air bubbles comes out of the bleeder.
At this point you should be ready to ride.
If you still don't have pressure on your lever, you need to take the brake master cylinder apart for repair.