Have you tried using Find and Replace? Click on Edit Replace. When
the dialog box appears, click on the More button so it expands. Ensure
there is no text in the Find box. Place your cursor in the Find box,
then click on the Format button, choose font, and select 8 from the
font size drop down. Click on OK. Now place your cursor in the
Replace text box. Click on Format, Font and choose 9 from the font
size drop down. Click on OK. You can either click on Find Next and
replace each item idividually or click on Replace All which will find
all text which is Font Size 8 and replace it with Font Size 9. This is
ok, unless of course, there is other text which is a font size 8 which
does not need replacing, in this case use the Find Next and replace
each instance.