Giving your cat any type of medicine can be a difficult struggle of wills. Nose drops, however, are often easier to apply than other medicine.
If you do have to give nose drops, be careful and gentle. It's best to take your cat on your lap, with her back to you. Pet her and talk to her soothingly. Then tip her head back so the nose points upwards. Apply the prescribed number of nose drops to the nostrils. Your cat may get scared and struggle, so make sure she's secure in your lap without hurting her. Also try not to touch the nose itself with the dropper, which may startle your cat and contaminate the nozzle.