To Modify Text Style
You can modify text style in any of the following ways:
Select the note. The Format tab appears. Use the commands on the Format tab.
Select the note and click Properties on the mini toolbar. The Note Properties dialog box opens. Use the options on the Text Style tab.
Select the note and click Format > Style > Text Style. The Text Style dialog box opens. Use the options on the Text Style dialog box.
Select the note and click Annotate > Format > Text Style. The Text Style dialog box opens. Use the options on the Text Style dialog box.
* 
If the value of the note height is set to less than 0.0014, which is the minimum allowable text height, the value automatically switches to the default height specified in the drawing_text_height Detail option.
If you change the style assigned to note text, you can change other text strings to the same style using Repeat Last Format. Select the text or note you want to modify and click the icon. The last selected style is applied to the selection.