What are you talking about?
Change the program language? Change the settings in the Creative Cloud application and change there the language. If your OS has a different language you might uninstall the old installation beore.
Change the text language for checking and hyphenation? Redefine Paragraph and Character styles and choose the language you need.
Change de program language, Change the program language. I changed the preference in CC, but it did not work. THs
Use the Gear icon in the upper right of the CC Desktop Application to change the language, then you can download the correct version of ID to support that language from the Apps tab.