Move attribute out
The Move Attribute Out refactoring allows you to move all attributes that match the name of the selected attribute in tags with the name of the corresponding tag to the corresponding parent tags. This bulk modification of attribute values may be useful as XML schemas evolve.
Moving an attribute to the parent tag
Place the caret at the attribute to move to the parent tag, press Ctrl+Alt+Shift+T, and then select Move Attribute Out from the list.
In the dialog that opens, specify the scope to delete the attribute in.
With the Directory scope specified, select the Recursively checkbox to include sub-directories.
Select the Limit to files with DTD:... checkbox to limit the scope to the files with the same
DOCTYPEas specified for the current file.

Invoke the refactoring:
Click OK to continue immediately or click Preview to have WebStorm show the usages of the selected attribute in the Find tool window where you can mark usages as included in or excluded from refactoring.
Click Show XSLT... to view a fragment of the XSLT that is equivalent to the requested refactoring. This fragment can be used by XSLT processors to perform the requested refactoring on files outside your WebStorm project.