Dog Aggressive When Putting On Leash?

My 4 yr. old (Cockapoo) dog has always been tempermental. We tried obedience training when he was younger and he bit the trainer. In the past year, he has become aggressive when going to put his leash on and will go to bite whomever is trying. Unlike our other dog, he hates walks, so he doesn’t go with often. I need some suggestions on how to rehabilitate my dog. How do I get him on the leash again without getting bit?
He gets kennelled several times a year and I think that is where the problem started. He needs to get kennelled in a week and I need to try to elimnate a 1 hour battle to get him on a leash.

How Do I Make My Puppy Walk Like A Normal Dog On The Leash!?

I have a 6 month old cockapoo. When take her for walks, she wants to smell everything, greet everyone and bites the leash, thus making me impossible to walk her.
She basically pulls me, and she looks like a Jackrabbit when I take her on walks!!!
So any training tips, suggestions, ideas to help me??
Thanks