1. Choose Edit->Find & Replace... 
  2. Specify the text you want find as described in Finding Styled Text
  3. Enter the text you want to replace in the Replace: box.
    If you don't want to change text text but just affect it's font, colour or size, remove the tick from the Replace: checkbox.
    Infix Find and Replace dialogue box
    Un-check Replace: to leave the text as is, changing only it's font, size or colour and alignment. In this case, the Replace and Replace All buttons will be disabled until you choose a Font, Size or Colour change to make.
  4. To set the Font, Size or Colour you wish to use for the replacement text, click on the reflow line, align auto hyperlink.
  • To do font replacement with this dialog (rather than using the Replace Fonts dialog), un-check both the Find: and Replace: check-boxes and set-up character formatting for both the find and replacement.