you need to be firmer with him and become the dominant party, using some simple exercises that you can do in your own home. you need to stand tall without being ridged and you need to relax at the same time. you must never back down to him and walk away, because in the dog world this means that you have submitted and backed off and he has again won. you need to always be calm and assertive when doing any exercise with your dog. you can practice dominance when out on walks. dont let her got out of the door in front of you and dont let him walk in front of you unless you give him the leway.

when you take him for a walk, you can put the collar right at the top of his neck, like you see on crufts. this will give you total control of his head and body, making him follow your lead and if he doesnt want to walk dont stop and take him back inside. just keep on walking, he may resist for a few moments but be consistent with him. with having the collar very high up his neck, he will look like he is on tip toes, which is what you want. if you just keep on walking and dont stop then he will eventually start walking normally with you without any problems. once he has achieved this you can praise him and give him a treat. by the end of the walk he will be more comfortable with you and will carry on being happy on the lead when out with you. if this doesnt work straight away, dont be dishartened, its normal and he will soon come round to the idea if you dont give in and just continue putting the collar high up his neck.

this is aproven technique and i have used it with previous dogs i have had, also see the dog whisper cesar millan, he uses the same technique to get dogs moving on the lead.

hope this helps, let me know how you get on!
if you need any more help then please let me know and i will try to help!