Getting out of work-related thoughts is really challenging. Unknowingly many times you will find yourself thinking something about your work. And I guess we all will agree that this is not good for our personal life. But many of us are clueless about how to attach ourselves.
Before we talk about detachment from work-related thoughts we have to evaluate our personal and professional life first. Because many will not agree that it's a harmful act. I know you will find many who are too attached to their work and it seems like they don't have any personal life. No matter what type you are, just accept that it's harmful and detachment is not bad.
Detachment doesn't mean you can't check your mail during the weekend if necessary. But it's more like making ourselves mentally detached from the continuous work-related thoughts. It's not easy to stop work-related thinking, especially when you are a responsible one. But believe me, this detachment can make you more productive, more attached to your personal life, and bring more value to your whole life.
Just stop thinking 'what if'. Don't think about what others said, what could be if you don't do that, what you need to do to make it work, ie. You will find most of our thinking is unnecessary, unproductive, and useless. They are just thought bubbles, doesn't add any value to your work life. So whenever something pops in your mind, just stop your thinking process right there.
Moreover, attach yourself more with people in your personal life. Bring more positivity and value to your life through different actions life going outside, hanging with friends, etc. Split your personal and professional life and don't mix it. It will take time but I can assure you if you continuously put intentional efforts to make yourself detached, you sure can do that.