I'm probably going against the grain here but you could always try just leaving the doors ajar, getting on calmly with your daily routine, and see what happens.... It might be that after a day or two of hissing and the odd bout of fisticuffs that they get over it. They must all be fairly fed up of the situation by now.
P.S. feed them some of the delicious cat-calming treats that I mentioned before.
P.S. feed them some of the delicious cat-calming treats that I mentioned before.