I boiled 2 lbs of dme in about a half gallon of water, cooled and added about 24 hours after fermentation took off. Just like duboman says. Just be careful of boilovers, use as little water as possible but the high concentration boiling will boil up and over real quick if you aren't paying attention.
No yeast, no beer. No beer, no civilization. Therefore, we really have yeast to thank for all our modern-day conveniences and tasty beer