You can edit a label that is included in a block using the Open command on the block shortcut menu. If you select the Open command from the Block Library, then your edits update the master block. If you select the Open command from the drawing sheet, then your edits update the block occurrence.
Right-click the master block, block view, or block occurrence whose label you want to edit, and then click Open.
Edit the label as desired using options on the Block Label command bar and the Block Label Properties dialog box. For example:
You can change the label origin point by typing coordinates in the x and y text boxes on the command bar or by dragging the label to a new location on the block.
To select a style override, select one from the Dimension Style list on the command bar.
To change label properties, click the Properties button on the command bar.
When you are done editing, click Return on the command bar.
The block label edits are saved with the block definition and the editing window is closed.