**A version that replaces tags, too!**

Here's my version of the "update page" script that will:

* Delete tags defined in `tagsThatShouldJustBeRemoved`
* **Replace tags** defined in `tagsToReplace`
* Adds a `*` to the page title to indicate that the tags were updated

.

    // ==UserScript==
    // @name       Burn/replace tags
    // @version    1.0
    // @description  Replace/Delete tags
    // @match      https://stackoverflow.com/questions/*
    // ==/UserScript==
    
    // Only run on pages with questions (question number in URL)
    
    if ('0123456789'.indexOf(window.location.pathname.charAt(11)) === -1) return;
    
    function exec(fn) {
        var script = document.createElement('script');
        script.setAttribute("type", "application/javascript");
        script.textContent = '(' + fn + ')();';
        document.body.appendChild(script); // run the script
        document.body.removeChild(script); // clean up
    }
    
    window.addEventListener("load", function () {
    
        // script injection
        exec(function () {
    
        /* add other tags that should get REMOVED but don't indicate the question is deletable */
        var tagsThatShouldJustBeRemoved = ["amazon"];
        var tagsToReplace = {'aws-athena':'amazon-athena'};
        var tags = $(".post-taglist .post-tag").map(function () { return $(this).text(); }).get();
        var toSave = [];
    
        $.each(tags,
               function (index)
               {
                   if (tags[index] in tagsToReplace)
                       toSave.push(tagsToReplace[tags[index]]);
                   else if ($.inArray(tags[index], tagsThatShouldJustBeRemoved) === -1)
                       toSave.push(tags[index]); // save it
               });
    
        // No change? Exit!
        if (toSave === tags) return;
    
        // No tags? Tell user.
        if (toSave.length === 0){
            alert('This question has nothing but bad tags on it.  Either figure out a valid tag or flag and ask a mod to delete it if it is hopeless.');
            return;
        }
    
        var id = document.location.href.match(/\d+/);
    
        // Saves new tags
        $.ajax({
            type: "POST",
            url: "https://stackoverflow.com/posts/" + id + "/edit-tags",
            data: { fkey: StackExchange.options.user.fkey, tagnames: toSave.join(" ") },
            success: function (x, status, error)
            {
                // Indicate update by adding a * to title
                document.title = '*' + document.title;
            },
            error: function (x, status, error)
            {
                alert(status + "\\n" + error);
            },
        });
    
        });
    }, false);