If you are using the new Blogger interface, please check this article instead.

You can add the Print Friendly & PDF button anywhere in your blogger template.

You'll need to manually add the code to your template.

Step 1: Get the Print Friendly & PDF button code. 

Step 2: Select Blogger as first option.

Step 3: Choose Print/PDF button style.

Step 4: Choose add code directly to template.

Step 5: Copy paste the code.

Step 6: Goto your blogger account, click Design, Edit HTML, and put a check mark in Expand Widget Template.

Step 7: Paste the code inside your template above or below the article (see image below).