You can always try this:
Turn your bars so the front brake master cylinder is at its highest point.
Squeeze the front brake lever and tie off with a zip tie or whatever you have available to the front grip.
Leave it like that over night and come back tomorrow and slowly release the front brake lever.
All of the bubbles should have risen up the brake lines to the top and are waiting for you to let them back in the master cylinder
Take care,
Dave