In a requeening situation, I have seen the attendants be attacked when released, but the colony went on to accept the queen.
You can use two queen cages to separate the attendants from the queen prior to release. Hold the cages end to end and use you fingers to close up the hole when you need to. Let the attendants go into the new cage, put your finger on the old cage's opening to keep the queen in there. You may have to repeat this process several times to get all the attendants out.
Also, at the state beekeeping meeting this spring, several times I heard speakers say to wait 5-10 days before doing a hard release of the queen. The rate of queen acceptance is much greater that way.
This month I installed 2 packages of bees. I waited 5 days before releasing. When I went in to do so, the bees had encased the queen cage in new comb. I had to cut out the queen cages away from the comb to release.