An easy way to requeen a colony is by using a queen cell. I think it unfortunate that many beekeepers overlook or reject the use of queen cells for requeening colonies.

I accept there are a number of different circumstances when using queen cells, but for simplicity I have assumed the beekeeper wishes to simply replace a laying queen with a queen cell and there are no existing queen cells in the hive.

I suggest one of the three following options after removing the existing queen:-

Option 1.

Leave queenless for at least 6-8 hours, preferably until next day.
Introduce ONE queen cell.
Option 2.

Introduce ONE protected queen cell immediately. This is likely to be more successful if the cell has at least 24 hours to go before emergence. I have had a number of failures if the queen emerges too soon after removal of the laying queen, as if the bees aren’t expecting her so soon.
Option 3.( My least favorite option)

Leave queenless for 7-8 days.
Remove all emergency cells.
Introduce ONE queen cell.
Because the queen was recently removed in options 1 & 2, the colony will probably build emergency cells, so check 3 days later and remove any, otherwise the colony may swarm with the virgin queen from your queen cell.

I like to check a day or so after emergence to see that the virgin queen is O.K. It is surprising how many these days emerge with deformed wings. Do it after about 5.30 in the evening, in case she is on a mating flight.

Once the virgin queen has emerged and you have checked that she is O.K. it is best to leave alone for a couple of weeks before checking for eggs.

I like to requeen with a queen cell, because the queen is mated from the colony where she is going to lay. It is much more successful than introducing a fertile queen.

With this method there is going to be a brood break. If there is a nectar flow at the same time, there is little or no brood to feed, so the colony can concentrate on storing honey. On many occasions I have had a colony fill a super in a week in similar conditions, so be prepared to add a super.