Shape a piece of wire mesh, which you can purchase at any hardware store, in to a cone shape leaving about a 1/2 inch opening at the small end. Fasten the mesh into shape using wire to secure the edges together. Make the larger end the same size as your stove vent.
Secure the large end of the cone over the opening of the stove vent using additional wire. This cone shape will confuse the bees, allowing them to exit but preventing them from reentering. It is best to do this step in the early morning or late evening when the bees are asleep.
Fasten a hive box, also known as a nuc box, next to the cone opening. This box needs to be within 1 foot or so of the exit. The purpose of this box is to provide the bees with a new place to hive. Without this, the bees would likely find another inconvenient location in your home to hive. These hive boxes can be purchased at many garden stores or farm supply stores.
Monitor the bees for the next few weeks. If you see bees reentering through the mesh cone, fasten a second mesh cone over the first, leaving a few inches between the first and second opening. This will confuse the bees further. Watch the interior of the stove for falling debris or bees resulting from the abandoning of the hive. If this occurs, you can fasten tinfoil or sheet metal on the inside opening of the stove to catch the debris.
Remove the nuc box and the entrance cones once you have observed no more bees exiting from the cone for at least a week. You can place this nuc box in an area where the bees will be less intrusive, not close to any inhabited structures. Beekeepers in your area may also want the additional bees.