I've only watched some of Danny's video, which looks helpful. I'm no expert, but would suggest keeping lots of treats with you, and any time you walk past another dog, feed him treats constantly at first, so he is focusing more on you and being rewarded for not lunging.
It also depends on the reason... does he need more playing with other dogs? Or, if you think there is any aggression, fear or defensiveness to it, it would be worth putting a muzzle on as well- at least for now. The last thing you want, is a dog that isn't fully under control, that may also cause injuries.
If it is playfulness, tire him out as much as possible first, safe and off-lead, if he has recall... and practise somewhere safe. If you know anyone with friendly big dogs, see if they can meet up with you, when he has had more training.