Attach a brood comb with eggs to a top bar, (several ways to do this) and just shake the bees into it, the queen can be in either box but Better if she is in the TBH. Leave the TBH and move the Lang about fifty yards or so away. The lang will need to have some stores and you should feed both for a couple of weeks, I just use a community feeder, can be several inverted jars. The TBH only needs the nurse bees that were on the one comb.