When you delete a style, you can
select a different style to replace it, and you can choose
whether to preserve the formatting.
Select the style in the Styles panel.
Do one of the following:
Choose Delete Style from the panel menu.
Click the Delete icon at
the bottom of the panel, or drag the style to the Delete icon.
Right-click (Windows) or Control-click (Mac OS)
the style, and then choose Delete Style. This method is especially
useful for deleting a style without applying it to the selected
cell or table.
Select the style to replace it.
If you select [No Table Style] to replace a table style
or [None] to replace a cell style, select Preserve Formatting to
keep the formatting of the table or cell to which the style is applied.
The table or cell preserves its formatting but is no longer associated
with a style.