Yep. You'll need to set aside a bunch of little sessions over a few days to help get your dog into a new state of mind, but it should be doable. You'll be using classical conditioning to establish a positive, eager response to the scissors.
Something like this, maybe.
- First off, get a new pair of scissors to use. One that looks as different as possible from any previous ones. Gimmick it up if you need to - put a bow on it or something. Dogs are terrible generalizers. Usually this is a pain, meaning you have to teach your dog the same trick in many different situations. But in this case it will work for you, as he's less likely to have generalized to "all scissor-type things"
- Now, get a big bag of awesome treats. I'm a big fan of Natural Balance rolls - available at all pet supply places and easy to cut up into bite sized bits. But anything tasty and smelly should work, like cooked chicken pieces. Don't skimp and use dry biscuits - you're trying to overcome a fear here, so you want to pull out all the stops.
- In a calm environment, give him a quick peek at the scissors. A second later, give him a treat and hid the scissors. Wait a few seconds. Repeat: bring out the scissors, give a treat, hide the scissors. Repeat many times. Make sure to vary the amount of time between appearances. Basically, you're going for "
When he is visibly excited about the appearance of the scissors (tail wagging, smiling), move them closer and repeat the process. Move up to having them right in front of his face. (Take your time. This whole process may take 2-3 days of periodic 10-20 minute sessions.)
- Now hold them right up to his nose and see if he'll sniff them or touch them with his nose. The moment he does, hey, treat!
- Start touching him with the scissors, always treating after each touch. Again, be sure to vary the moments between touches. "C'mon, c'mon! Touch me with the scissors already! I want a treat!"
- Once you've moved up to being able to touch him anywhere on his body and have him happy for it, back up a step. Have him see the scissors in your hand and make a little "snip" motion with them - and treat. Repeat, getting closer and closer, making little snip motions around his body (not touching him).
- Once you're sure he's cool and happy with the snip-snip sound, and is eagerly awaiting his treat, time to back up a step again - now have him lie down while he sees the scissors in your hand and you're touching/holding him the way you would to groom him. Repeat.
- Now that he's cool with you holding him while making little snip-snip motions all around his body, go ahead and snip a TINY piece of hair. Probably best to end that session there.
- Next session, do some snip-snip motions, then snip a little piece of hair, then just some motions again. Work up to more and more hair being cut.
- Voila, you're cutting your dog's hair and he's thrilled. Start phasing out the treats, till maybe you're just giving him only one at the very end of a grooming session.