Through file migration or copy and paste, you may have a file that has an unwanted style, such as a dimension style. Use Replace Style to replace the old styles with a new style to make all styles uniform.
Replace Style substitutes all references of a style with another style of the same type, including object references to styles and style references to substyles. and style and substyle references. Only local styles are replaced.
Styles and Standards panel
Styles Editor. If desired, select the Purge Replaced Style check box to purge the old style automatically.