Browse to the PDF you want to display in the message ... Just look for the "Insert Image" or "Insert Picture" link or icon in the program window. To attach the PDF file to the message, click ...

An icon in the shape of a lightning bolt ... you may find yourself accessing many PDF files. The default PDF viewer on Mac computers is Preview — but you can easily switch it with a few clicks.

PDF Reader Pro is ... Instead, a row of icons above the document pane provides access to editing functions. Another set down the left side lets you view the current document as thumbnails, change ...

but if you really hate the change and want to revert, keep that in mind. The new PDF file icon, for Windows users who have Google Chrome set as their default PDF viewer.