Select the style in the panel, then either double click ther style name, right click and choose Edit Style, or open the panel menu and choose Style Options to edit, or reformat some text using the style to be thway you want it and either right click the style or open the panel menu and choose Redefine style.
To delete a style you can drag it to the trash icon or use the panel menu. If it's in use you'll be asked to choose a replacement.
Thanks a lot! jejeje it was so easy edit a character style, I wonder why I don't see it before. The same with the delete option.