I have been very blessed in that all my friends have been very supportive of my choice to quit drinking. It does mean, though, that I receive far fewer invitations for evenings out than I used to. However, I still socialize with the true friends of mine - we just do different things. I often meet them for lunch instead of after work for drinks. Other friends of mine invite me out for dinner. Or I will hang out at a friend's place for an evening and bring my own non-alcoholic beverage.
It is a big change, particularly when our worlds were all based in pubs holding drinks. But as a lot of people can attest, it definitely can be done. Although things won't be the same, I can assure you they will be better. You will find a few high quality friends which will give you a lot more than a huge crowd of people who just sit around and drink and tell the same things over and over again.