Unable to find "back up" HTML to enable me add LinkedIn share button to my blog


I requested help to add a share button of LinkedIn to my blog and I was given about 4 steps to follow in order to do this. However, on getting to step 2, which says “back up” your template, I cannot find the tag. All effort to search it out failed. Is it that my template does not have this tag. Can you guys help me sort this out please. Thanks.