In Blogger, go to the DESIGN tab, click EDIT HTML.
Paste the code at the bottom of this post into the HTML at the very bottom, but right above the part that says
If you want to change the color to match your blog, find the part that says
(its in the first few lines of code) and change the color to whatever you like (HTML color codes HERE)
If you want to change the number of sparkles, find the part that says
(its in the first few lines of code) and change the number to suit your needs.