A vacuum pump works wonders but you can just gravity bleed the MC. Once you have everything reassembled just pour in the new fluid. Open both caliper bleeders and leave the cap off the MC. The fluid will flow through gravity down through the MC, once you get the first hint of fluid from below close the bleeders. Very, very slowly pull the brake lever back some. Be careful and slow because it will spit fluid up and everywhere. You'll possibly see a few bubbles come up, stroke the lever a few times until no air is seen up top. Again, very slowly and don't worry about pressure or feel. Stop once you feel pressure or hit the grip.
Once it's clear up top you can now bleed normally. Fill the MC, put the cap on, stroke it three times and open one bleeder. Repeat until the first bleeder is clear then move to the other. Check your fluid level every third or fourth time you open the bleeders or you'll be starting over.
You may have to crack the lines up top to get the last remnants of air, once done bleeding you can have an assistant hold the lever down under moderate to a little light pressure. Put the wrench on the banjo bolt, wrap a rag around the works to catch fluid but where you can just see the washers and lines let the air out, break the bolt loose slowly. You'll only have to do that once but checking again doesn't hurt. The guys that say to zip tie the lever down over night, that's the air they're getting. Under compression and left that way the air turns into smaller bubbles, moves into the MC and comes out when you turn the lever loose.
I personally have a reverse bleeder, it feeds fluid under pressure from the bottom up chasing the air out naturally, they're usually the best but pricey, usually 3-4X a vacuum setup like above.