How do I bleed the brake line after been totally empty and refilled?

Jason is right reverse bleed but the easiest way is to get an oil can from the hardware store, add a small piece of hose the same size as the nipple, and fill the can with brake fluid (dot 3/4 please), and pump the can until it bubbles at the reservoir, then tighten the bleeder screw, should be great after that.

put a plastic pipe on to the bleed nipples and the pipe into some brake fluid in a container or bottle, open bleed nipple and keep pumping till the brake builds up and most of air comes out , do other nipples the same. then go back over in slower more build up motion. until you have a good brake . and keep remembering to top fluid up all the time.

you can reverse bleed it .

to do this use a bottle with a bit of pipe on it. fill the bottle with brake fluid then put pipe on bleed nipple press the bottle then that the bleed nipple off and push the Fluid up the line you should see the Fluid in the filler bubbling

try that is a fast way to do it.

add oil to resavoir, pump ,hold, open bleeder, close, watch fluid level. got rythem?