bliss's tag-fixing features work in a similar way to the rest of the bliss functionality. First you configure bliss to check the accuracy of your tags, bliss then scans all of your music to ensure your tags are correct, and finally you can click simple one-click fixes to correct those tags.
You can also perform manual changes out-of-band to the accuracy checks. If you have tag correctness enabled, those changes will, of course, themselves be subject to bliss's assessment!
However, if you want to get on with fixing your tags, click to advance to the next step.