Varroa control with drone brood
Normally you put a shallower frame in the brood box, ie a super frame in a standard national deep brood, put it at the edge of the brood nest. The bees will draw it out full length to match the rest of the frames by just building on the bottom, this time of the year they will draw drone cells.
When they are layed up and sealed simply cut the whole lump off and stick it in the freezer or feed it to the chickens before discarding it / melting it down. ( Freeze it to kill the lavae and the associated varoa which are breeding in the drone cells.)
Replace the frame and repeat. Later in the season they will build worker cells instead of drone.
Best advice is after 2 cycles of drones replace it with a normal frame and put the shallow frame in the super to allow workers to hatch.
To remove drone brood from a comb itself: Just use an uncapping fork when the drones are at ‘pink eye’ stage. Run the fork under the cappings, pry upwards removing all the drone larva and varroa.
Feed the larva and varroa to chickens (if available) and return the frame to the hive to get cleaned up and more drone brood put in.
Do not let the drones hatch as you will be increasing your varroa load substantially. A hive needs some drones so do not remove all of the drone brood, leave a bit. (from Beekeeping for Beginners)