"How to change the text in a bookmark"

I want to replace the text entered in the bookmark after importing bookmarks in the office.

Is there a separate object like replace?
Or if I want to delete the text in the bookmark and insert new text?

Hello @Hyun

Do you mean the name of a bookmark?

If so then the only way is to get range of a bookmark, delete old one and add new on the same range:

    var oDocument = Api.GetDocument(); 
    var oRange = oDocument.GetBookmarkRange("<current_bookmark_name>");

Methods used are GetBookmarkRange, DeleteBookmark and AddBookmark.