I always use the hosted code at alxgorbatchev.com.
Step 1. Log in to your blog dashboard
Step 2. then go to LAYOUT >> EDIT HTML
Step 3. Right before the closing head tag, add this css files
Step 4. Then add these js files at the bottom of the page, right before the closing body tag.
Step 5. All you have to do now is to write the real sourcecode to be shown with the highlighter. For example,
That will do it. You will have a prefectly running syntax highlighter now. Enjoy!