I did one similar a couple of years ago. Taped my knife to the end of a long stick to cut the combs and another long stick to let the comb sit on and pull it out. Home owner gave us an old curtain rod that had a bend on the end of it, made a good hook to work combs around with. Used my bee vac and fashioned a long skinny nozzle out of old campaign sign and taped a small LED flashlight on it to see with. A couple of cotton balls soaked in bee-go or the like and placed on the end of a long stick and pushed to the back side of the combs to drive the bees out towards you and the bee vac works good too. It was a real chore and my arms were tired and sore the next day. Kind of like using chopsticks to fish out the combs.
Good luck!