Need help changing email

Back around the time the handsome collection came out i signed in with xbox and now i can only sign up with the xbox button that appear in the sign in part of shift and would like to know if there is a way to change the xbox sign in to a normal email sign in.
Edit: I feel like some people will say to press the button that says edit when in my account details, but it always says incorrect passwords and i changed the password with using the previous password correctly.

You should contact SHIFT support https://support.gearboxsoftware.com/hc/en-us/categories/200330390-shift