How to: Clear only the format of a cell.
Solution:
Select 'Clear' from the 'Edit' menu and select 'Format' from the submenu.
1) Select the cell or range with the format to be deleted.
2) Select the 'Edit' menu and select 'Clear'. (A submenu appears.)
3) Select 'Formats' from the submenu. (The format of the cell or range returns to Excel's default Normal format.)
the Formats command