I have Haglund's deformity in both feet. The main bother it causes me is that I can't wear 'normal' shoes, so live in trainers.
What symptoms do you have, other than the bone prominence? Once it's calcified it's not going to go away, so if you can focus on not irritating it then you might be able to avoid surgery (assuming that's what you want to do).
Personally, I want to avoid surgery for as long as I can. I was told that it may be necessary to cut the Achilles tendon and there is no way I'm volunteering for that for the sake of wearing fancy shoes! I'll keep my trainers and my tendons intact
I think stretching the Achilles can be helpful, and making sure that your footwear doesn't rub is essential.