If DesignCenter is not already open, clickTools 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.