Hi, take a frame with sealed brood on it, shake all the bees off and put that into the weaker hive. The young bees will soon emerge and add to the numbers in your weak hive. You can then do another frame in about a week or so's time if all is well. This way it won't strip your good hive too much.
Obviously replace the frame you take out, and make sure they have sufficient food in the weak hive, if not give them some syrup.