
What have you tried so far? :) I would clicker train it myself. Get a toy or food, show the dog lead and collar, click and reward, put collar half way over dog's head, click and reward, put collar on dog, click and reward, put collar on, ask dog to move one step (movement may trigger the excited grabbing), click and treat for not biting the lead. Remember to mix it up and sometimes go back to showing the dog the lead and click and reward so that he realises that any part of the action of you placing the collar over the dogs head, moving the dog around is an opportunity to gain a reward by acting appropriately. You may find that getting to new places will stimulate him to "act up" and this is where you need to build the behaviour back up again.
Just build it up so he knows that he has access to all the fun he wants by choosing not to grab at his lead.
He is a baby, and a lovely one by the sound of it :) you don't want to crush his spirit. Use his attitude to your advantage :)
If you'd ever seen me in the ring, however, you'd disregard all of that :D
Jess