If DesignCenter is not
already open, click Tools menu Palettes DesignCenter.
Right-click
a block in the DesignCenter content area. Click Redefine Only or
Insert and Redefine.
NoteIf
the source of the block that you want to update is an entire drawing file
rather than a block definition within a drawing file, right-click
the drawing's icon in the DesignCenter content area. Click Insert
as Block.
Palettes 
Toolbar: Standard 
