Did your CPU come with an instuction booklet? Maybe this is of help:
http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/23986.pdfYou will need a slot screwdriver. A fair bit of force is needed to clip it on... if you can't get it, or are worried, take it to your local computer shop... they should clip it on in a few seconds.