Any tips on bonding male and female rabbits?

Hi ladies i recently adopted a spayed female and a neutured male rabbit and have been unsuccessful in bonding them. I have tried placing the cages close to each other, intermittently switching the rabbits over into each others huthes so they can get used to the scent and also facw to face time. However both rabbits start fighting and when you stop them they just sit as seen in the picture. I dont know what to do.